So far this morning there was no good reason Twilight Sparkle had come up with as to why she should bother to open her eyes. The heavy rain, -yet more unscheduled weather it seemed- pattering against the thick glass of the small square window on her left sounded so much like how it had all thoes years ago when she still lived in the Golden Oaks Library that her drowsy mind could almost imagine she was still there on her narrow but cozy bed, and that Spike would soon be coming up the stairs to ask her what kind of berries she wanted on her pancakes. It was just all too comforting and peaceful for her to want to do anything other than lay there quietly and listen. The damp scent of the rain made the room around her even smell cozier. If she could just keep her eyes shut a little while longer, then that was all the more time she could enjoy the comfort of the past.

Even after all these years, the only thing that kept her tears from trickling out at the thought of what had happened that awful day was knowing that growing in the very center of the wide shallow depression that had once been the charred blast crater marking the place her home of many years had stood, was a lively young oak tree sapling now three ponies high. Applejack, Faust bless her, had grown the thing from an acorn off the original library tree itself. It would still be a few decades until it was as high as the original. Unfortunately, height was only one consideration, for the trunk to be wide enough to build a new library inside…that would take centuries. She could, technically, use a large quantity of magic to force the tree to grow to full size within minutes, but that would result in something a bit artificial looking, it would lack the gnarled structural majesty of a tree grown naturally, and would not be entirely trustworthy from a safety oriented standpoint. Magically derived structures were notoriously unpredictable. And besides, it was unbecoming of an Alicorn to inhabit a ‘new’ home. Canterlot Castle was a millennium old, and the Chrystal Palace, well, that might be a hundred times older still for all ponies these days knew.

‘And as I’m an Alicorn now, I suppose I can wait.’ Twilight thought to herself, eyes still closed. Patience was after all, at least in this instance, a virtue.

A slight movement, a shuffling, and now a gentle nuzzling, brought Twilight out from her considerations on the issue of appropriately grown housing. Incidentally the movement, that of another pony, finally gave her reason to open a single eye. The small bedroom was suffused with a dim light that seemed to trickle in the window much like the raindrops running down the glass. But the light brown wall paneling and timber frame supports lent it a coziness that many a pony would pay some designer handsomely to replicate, probably imperfectly, in their Canterlot townhouse.

Why was it, Twilight wondered idly, that the majority of ponies, her friends included, had manes and tails of a single color or pair of colors, which either nearly matched or in some other way complemented their fur color, but then, once in a great while, a pony would come along with a color pattern that defied convention so blatantly? Both Cadance, Celestia, and herself had three colors in their manes, which was unusual enough, but the pony whose head was pressed up against her right hip –now how had that happened? Had six.

She considered, not for the first time, how many mares, along with most of the stallions, living across the continent of Equestria, lusted after the rainbow maned pony she was laying on the bed with right this moment.

Twilight was not usually a pony to be smug…but that thought, well, that often did it.

Rainbow Dash had a strong, sleek, and youthful body that was always kept in great shape. It had taken Twilight years to figure out that Rainbow didn't just stay healthy for the sake of her goal to become a member of the Wonderbolts, a goal achieved years ago, or as a generally good life style choice, but because there were few things the Pegasus enjoyed more than to be the one who could outlast, outplay, and generally defeat any opponent in any game or event she came across. Her competitive streak was a kilometer wide. This determination to be the victor was rarely more apparent than when it came to sex.

She wasn’t necessarily the dominant partner in her relationships, a fact that had initially surprised Twilight early on in their friendship. She could be unquestionably submissive when she wanted to be, but nothing made her more insufferably pleased with herself than making whichever mare she was with that night cum before she did. Her body, and the shape it was in, allowed her to achieve victory quite often. For a decade Twilight had worked to keep up with Rainbow several times a week. Only after her ascension, a year ago now, had her new and improved physiology allowed her to keep up with, and some nights even win out against, her partner. Perhaps that's why Dash was spending even more time with her recently, she did love a challenge that one.

Twilight considered turning onto her side, she had slept the whole night through on her back, an unusual thing for a pony, and the ache developing between her shoulders was a reminder of that fact. But doing so would disturb Dash, and besides, laying on her side would put pressure on the crotch of her diaper from whichever leg was on top. If it had been dry, that wouldn’t be a problem. However, it was anything but.

The diaper had already been rather wet when she had gone to sleep, completely exhausted by her eventually successful attempt at making Rainbow cum first, an accomplishment swiftly followed by promises of retribution. Now, since having woken up twice during the night to use the bathroom but simply letting it flow into the waiting diaper, it was quite soaked, and her bladder was beginning to ache anew. Her diaper would soon be at its limit and laying on her side was a guaranteed way to make it leak somewhere. What was the point of wearing one of the things if it was just going to do that?

Rarity made wonderful diapers, and they would expand to twice their original thickness when fully wet, but even they couldn’t go on forever. But as long as she didn't do anything too drastic she could stay in this one for a while yet.

‘Might as well get on with it.’ Twilight thought as the rain continued to pour outside.

It was really quite cozy, being in this warm bed in one of the naturally rustic bedrooms on the small second floor of Fluttershy’s cottage. Thank goodness it had a plastic sheet. Fortunately for the pair of them the cottage’s shy owner was typically a well prepared pony. Twilight knew that she would need to eventually get herself up and out for her business in Canterlot today, but first she was just going to remain lying here, wet herself some more, and enjoy how the addition of more pee flowing down and into the back of her diaper would make it even more enjoyable to lie in. Perhaps Rainbow would eventually wake up and relieve Twilight of the possible guilt of disturbing her.

No longer caring what her bladder did now, Twilight simply relaxed herself completely. It was a funny thing, Twilight knew that the spray of urine now flowing freely into her diaper was at precisely her body temperature, yet, it felt so warm, as though it must be a dozen degrees higher still. Perhaps because she knew her pee was warm, her mind made it feel that way more than it otherwise would have. It was something to consider.

Twilight was surprised when a light blue furred leg rose up and pressed its hoof gently down on the front of her diaper just over the gushing warm pee. Twilight smirked to herself, ‘how long had the little devil been awake?’ She wondered.

‘Well, no reason to pretend I am either.’ She realized, spreading her legs just a bit further, letting Rainbow know that she was well aware and approved of where the Pegasus’s hoof was.

The hoof began to rub around in small circles as Twilight continued to wet. In response she began to lift her butt up to press herself into the roaming hoof. Twilight knew that this escalation in her response would only ever end one way and that doing so would bring to a certain end any sense of a calm, drowsy start to her morning.

She didn’t give a damn.

Twilight’s diaper did an admirable job of absorbing yet another full bladder’s worth of stored urine into its thick padding, the dark stain nearly spreading into every corner of the diaper. However, it had long ago given up on being able to absorb the moisture enough to pull it away from her sensitive skin and lavender fur, giving her most enjoyable parts an all-but-literal bath underneath all the hot wet padding.

Twilight was disappointed when having finally finished her morning wetting, and the pee trickling to a stop, that so too did the hoof rub. Twilight opened her eyes more fully this time, and using her foreleg’s knees, raised her upper body off the pillows and bed so she could look down to see what might be done to get the hoof to resume its work.

Twilight’s diaper, one of a type designed by Rarity, had a good quality smooth plastic surface, one that wouldn’t tear when the tapes were pulled, that was a medium lavender around the waist and leg holes and a very light lavender everywhere else. Small purple five-pointed stars decorated the sides of the diaper and the tapes themselves were a light soft green color that Twilight wouldn’t normally have thought would go well with her coat but seemed to complement it anyway. The diaper certainly had swelled up nicely, the light lavender coloration of the plastic now seemed a bit off due to the mild yellow of the liquid it contained. The subtle yet obvious smell of a hot pee once again began to mix with the pleasant early-morning rain scent that had been so relaxing before. This new smell was another nail in the coffin of her morning drowsiness.

Right next to her thick and warm diaper was the upside-down face of a smiling pegasus who knew exactly what it was she had started.

Rainbow Dash quickly turned over and stood up from where she had been laying with her cheek against Twilights diapered hip upon seeing that the alicorn was now very much awake.

Rainbow stretched luxuriantly, showing off her own diaper. The diaper itself was a bit more streamlined than what Twilight had on, the plastic surface was thicker than a standard diaper, a functional choice Rarity had insisted on when designing it so that it would keep its shape better and stay smooth and sleek no matter how much walking, running, flying, or…other activities the pegasus got up to while wearing it. The waist of the diaper came up a little further on Rainbow than it did on Twilight, helping to keep the diaper’s image as one appropriate for an active pony due to making the diaper look even more streamlined. Most of the diaper was a light grey blue but with three wide parallel navy blue strips running from the top of the front all the way around to the tail hole in back. On top of the blue strips, front and center on the diaper was a large print of Dash’s cutie mark.

As much as Twilight loved seeing Rainbow in her diapers and how good she made them look, it took some effort to not immediately roll her eyes at the blatant example of vanity. Even if it was very cute vanity.

Looking up at the underside of Rainbow Dash from her position she could easily tell the diaper was soaked to bursting despite the diaper’s color not being one that indicated wetness as well as plain white plastic would have. That diaper had been completely dry when Rainbow had gone to sleep so far as Twilight could remember. Perhaps there actually was something to that vulgar joke about having to pee like a race h**se.

“So….ya’ like what you see?” Rainbow Dash asked, classic smirk fixed firmly in place.

“You know you don't need to ask that, not after what we did last night anyway.” Twilight responded, again trying not to roll her eyes.

“Hmm… about that, I seem to recall you…winning… that round.” Rainbow said the word as though it she was being forced to eat hoof tacks.

“I think it’s time for a little payback, and I’m not goanna let you leave here without settling the score, and from the way that diapers’ looking I won’t have to try too hard.” The six-colored pony said.

Twilight had to admit to herself that Dash was probably correct, bathing her pussy in hot pee while watching Rainbow in her own diaper had excited her to quite a degree. And frankly her desire to ‘win’ at, well, anything really, appeared to have departed her sometime during the night. Simply laying back and letting the pegasus get to work seemed quite alright with her.

“Ok Dashi, do whatever you want. I can tell when I’m not going to win.” Twilight said as she let herself fall back onto the smooth clear plastic of the bed sheet and spread her legs a bit wider in invitation.

Rainbow actually managed to look almost disappointed at the lack of any resistance from Twilight. Probably because getting Twilight to cum first didn't mean as much when the mare wasn’t going to do anything to try and resist her orgasm.

‘A hollow victory’ Twilight thought to herself with a private smirk that she made absolutely sure Rainbow didn't catch. This annoyance will only make Rainbow try harder to correct for next time they really went at it. It was rather devious, using Rainbow Dash’s psychology against her to ensure even better sex in the future this way, but then, any princess, even Celestia- actually, especially Celestia, needed to be able to be subtly devious from time to time.

A cool breeze began to blow between Twilight’s legs as the tapes were pulled back on her diaper. Rainbow did this job one tape at a time using her teeth. Not so much because she had to, but because it drew out the process, increasing the anticipation. Rainbow then pulled the front of the soaked diaper off Twilight and let it flop gently down between her spread legs, exposing a lot of pee soaked fur and a glistening slit at the center of it all.

“Huh.” Rainbow muttered.

“I’m surprised you haven’t messed at all since last night, you know, since you like to so much and all.”

Twilight tried her best to shrug while lying on her back.

“Haven’t had too I guess, and anyway, you know I don’t like to mess right before going to bed.” Twilight replied

Rainbow snorted.

“Yah, because it makes you too horny to sleep, all that poop in your diaper, you know, smearing itself all over your slick pussy…”

“Yes, yes, alright! Just get on with it Rainbow!” Twilight said in exasperation.

Some mares like Rarity would have then taken the opportunity to further tease Twilight by slowly drawing out her pleasure with a thousand little practiced tequnique designed specifically to make a mare ‘almost’ cum for hours.

Rainbow Dash, on the other hoof, having realized that verbal teasing time was at an end, dove muzzle first into Twilight’s pussy like a starving pony into a bowl of blueberries.

Dash was perfectly happy with eating out any good looking mare under normal circumstances but the smell and taste of piss along with the fresh plastic scent of the disposable diaper that held so much of the yellow liquid, was more than she could resist.

Twilight’s smooth cum-slicked lips were an utter delight beneath the pressure of her tongue, and knowing that they had spent the night being held protected and warm under all the soaked padding of Twilight’s diaper made this probably the best clit in all of Equestria Rainbow could have her tongue inside of right this moment. She made sure that not a single millimeter of the delicate flower under her muzzle escaped her attention and was rewarded with Twilight arching her back and groaning loudly at nearly everything she did.

Twilight for her part, once again found herself completely at the mercy of Rainbow’s abilities and with no desire to do anything about it aside form letting it go on as long as possible. She was still dimly aware of feeling the wet diaper under her butt adding its own pleasure to the experience.

When Rainbow opened her jaws wide enough to hold on to her whole pussy at once between her lips and jam her tongue into her clit, Twilight came into Dashi’s mouth as though she had released a quick hard burst of pee. She could actually hear it splatter across Rainbow’s teeth.

Suddenly feeling drained of strength, Twilight flopped back onto the bed with a loud sigh as Rainbow licked her lips and leaned in for a kiss. Twilight happily accepted and as their tongues intertwined Twilight was able to enjoy the taste of herself mixed with a faint bit of urine, which she enjoyed in small quantities such as this.

After a few seconds, which somehow seemed rather longer than that, they broke away and Twilight again levered herself up to a sitting position and from there onto all fours by half turning, half sliding out of the bed.

“Huh? You’re not going to put your diaper back on?” Rainbow asked looking mildly surprised. Probably taping Twilight back up into her already thoroughly soaked diaper had been the next thing on Rainbow’s list of fun and sexy things to do with her this morning.

“I’m sorry Rainbow.” Twilight said catching the sound of disappointment in her voice.

“I need to take a shower and get myself to Canterlot soon. I might take the diaper with me to put on later, but it won’t do to be seen wearing the thing all about in public.

“Well, I don’t mind seeing you wear one in public.” Rainbow said in her version of a reasonable attempt at earnest seriousness.

“I know you don’t, Dash.” Twilight said smiling.
“But there are some… interests that ponies enjoy that really don't fit well with their public lives. As you well know.” Twilight replied, almost taunting.

“The other ‘bolts know I wear diapers under my flight suit, Spitfire certainly does…” Rainbow couldn’t help adding.

“Maybe they do, but they are your friends and you all know quite a lot about each other’s private lives. How well would it go over if you performed at some large public event in just a diaper and no flight suit?” Twilight asked.

Rainbow quickly glanced down at her diaper and cringed at the thought.

“Ok, ok, point taken. A princess can’t show off thoes strong leadership qualities if she goes about everywhere in a diaper.” Rainbow said with a slight huff.

“Exactly. There is a time and place for engaging in one’s sexual fetishes and a time and place for good governance. Unfortunately, the two don’t often overlap.” Twilight said, knowing as she spoke that she was falling into the role of guest lecturer at the university.

Rainbow simply looked at her with a bemused expression while sitting on the edge of the bed in a way reminiscent of a certain mint green and white pony who could always be found in the same position on Ponyville park benches with her marefriend.

“Right, yes, well, time for my shower.” Twilight decided out loud, unsure of the best way to smoothly disentangle herself from this conversation.

As she trotted across the room the faint sounds of a giggling Rainbow dash followed her as she went towards the bathroom door. Not that Rainbow would ever admit to having ‘giggled’ about anything.

****

As a gentle spray of warm water from the little shower in the single upstairs bathroom washed the last of the night’s pee from her fur and the lightly basil scented shampoo made said fur shine again with a luster which had been lacking of late, Twilight considered Rainbow’s diaper and the way it looked on her athletic body. How its thick plastic surface always glistened with reflected light, looking almost wet, even when the diaper itself was dry. A bit ironic that. Also, how Rarity’s design managed to give the diaper a strong sense of thickness and bulk between the legs and over the butt without actually looking so bulky in the way a baby diaper often did. Twilight figured, not for the first time, that it had to do with Rarity’s expert knowledge of proportions. It was almost like the diaper was emulating the form of its wearer. Which, Twilight knew, was exactly the effect Rarity had in mind when she had made it, and all the others like it, for Rainbow. Some other athletic ponies, or so Rainbow had told her, made due with pullups. Not that pullups themselves were bad per-se, but Rainbow had insisted, and Rarity agreed, that the pegasus deserved true diapers, and the best possible at that. The pony tended to pee quite a lot and had never shied away from pushing a large squishy mess into her diaper whenever the need arose. Pullups simply were not designed to deal with all day, and sometimes all day and night use without a change. Also, no matter how much Rainbow managed to wet them they never seemed to swell up quite as much as Twilight’s diapers did. As though the absorbent material in them was slightly different. She really ought to ask Rarity about that at some point.

Twilight became aware that she was beginning to feel quite excited again just by thinking about diapers so much. Which was funny because a pony would think that having just been licked to orgasm by a mare like Rainbow Dash might have more to do with her present arousal. Well, in a way it had, Twilight supposed, but diapers were what made the whole situation too sexy to ignore.

Just as she turned the little metal handle with a hoof tip to turn off the water while concurrently fetching her towel with her horn to work on getting dry as quickly as possible, she had been thinking idly in the shower longer than was necessary after all, she became aware of a growing need to use the bathroom. The pressure sort of snuck up on her like Pinkie Pie was known to do when in one of her prankster moods. One moment she didn't feel anything, and by the next she knew that whatever she did it would involve having to poop in just a few minutes. There was no way to keep a feeling this strong contained for long.

“For the love of Cadance!” Twilight growled to herself with teeth clenched.

‘I’ve just spent the last twelve, no, fourteen hours wearing a diaper, and as soon as I take it off I have to go like this?’ Twilight thought to herself in annoyance.

“Ugh! How typical.”

“Although…”

Twilight suddenly realized that unless Dash was planning on going somewhere today that there was no reason she could see that the rainbow pony would have reason to take off her diaper while she had been cleaning herself up in the shower.

This meant that in a way there was still a diaper she could use where all this nice poop her body had been storing up wouldn’t go to waste.

Twilight emerged from the shower accompanied by a cloud of the warm steam that had built up to near sauna like levels in the small poorly ventilated bathroom. As soon as it made contact with the glass in the small windows of the bedroom beyond they immediately fogged up, obscuring the outside view completely.

To Twilight’s puzzlement Rainbow was sitting upright on her bed, her back to the wall and with her diaper untapped so the front was laying open between her legs. The once bright white padding was a light yellow color, and had been so since the previous evening. The new addition was a brown smear coating the inside of the diaper immediately under the cyan pony’s butt. Dash had a hoof pressed against herself near the top of her narrow pink slit. Its bottom half was coated in the same stuff that was under herself.

However, instead of being in the midst of pleasuring herself like Twilight had immediately thought, Rainbow seemed to simply be contemplating the situation between her legs with slight disappointment.

Seeing Twilight standing there with a questioning look on her face, Rainbow ‘s expression changed from disappointment to slight annoyance.

“I thought I felt like I had to go enough that I would make a poop that would be worth enjoying in diapers like this, but I didn't wind up going as much as I thought I would…”

Twilight could only smile broadly, thinking how this was turning out to be an even better situation than she had planned for.

“…What?” Rainbow asked with a suspicious look on her face, seeing how Twilight’s reaction was not the one she had been expecting at all.

Twilight didn’t say anything at first, simply removed the large fluffy green towels wrapped about her midsection and tail and stepped up onto the bed. With a burst of telekinetic power, she lifted Rainbow Dash, open diaper and all, away from the wall she had been leaning against, and laid her back down so that her head was resting on the pillow Twilight had been using when she had woken up.

“What are you up to Twilight? Rainbow asked, surprised at her sudden relocation. It was generally considered rude for a unicorn to touch another pony magically, to say nothing of lifting them up into the air, without at least asking permission first. Even when having sex, that was not something Twilight did much of. So doing it now, implied a certain level of impatience or arousal on Twilight’s part. Briefly Rainbow had time to consider that perhaps it was both.

“I’m simply assisting you with your current problem.” Twilight said.

“Now, scoot back a bit.”

Rainbow did so, shuffling her butt several centimeters back from where it had been resting on the diaper and revealing a modest mess. Certainly more than a skidmark, but rather less than enough to result in a properly filled diaper. Twilight understood her friend’s annoyance, it was the perfect amount of poop to feel just good enough in a diaper to leave a pony desperately wanting more.

Twilight was proud of herself for not rushing the procedure too much up till now, but she was a hair away from losing containment – so to speak, and doing so anywhere but her planned location would be a criminal waste. It was all she could do to keep her anus closed while getting Rainbow to adjust herself into the proper position.

As soon as Twilight was satisfied, she immediately stepped over to put two legs on either side of her on-again, off-again marefriend, positioned her butt just over a spot on the diaper that she calculated would be halfway between where the diaper would cover Dash’s anus and clit and relaxed all the muscles in her butt.

A huge load of soft squishy poop burst out of her rectum and flowed, glistening in the dim morning light, right down onto the exact spot Twilight had chosen. The consistency of the poop began to change from creamy at first to more liquid and runny towards the end, almost splattering out of her. The result was a large pile of soft light brown poop, slowly spreading outwards. Twilight couldn’t resist a sigh of relief as the pressure in her butt suddenly disappeared.

“There! What do you think of that?” Twilight asked Rainbow, who was trying to get a good look at the pile that was now pressing up against her butt as she lay there. The position was a bit of an awkward one for any pony because it required her to have her tail bent backwards underneath herself. Pony tails were very flexible, but they could only take so much for so long.

"Sweet Celestia Twilight! this is so nasty...and hot... mmmm..." Rainbow moaned as she slid her butt forwards in the diaper just a bit, pressing her pussy into the mound of squishy poop that was slowly spreading outwards.

"I think I should tape up this diaper before you just cum right as you are." Twilight suggested.

"Would that really be so bad?" Asked Rainbow.

"What are your plans with Fluttershy?" Asked Twilight with an eyebrow raised.

“Ah, right, well, uh, I guess you did solve my problem at any rate... Rainbow Dash said, a grin growing on her face.

Twilight simply smiled.

"Yah, well, help me get this thing taped on so I can get up then.”

“Ok, but the only way to make sure this works without anything squishing out the leg holes is to properly allocate the poop to as much of the inside of the diaper as you can.” Twilight responded.

Rainbow Dash smirked.

“You mean smear it around a bunch.” Rainbow said dryly.

“Yah… Twi, this isn’t my first messy diaper, ya know.”

“Ok, ok.” Twilight said, a little abashed. Though she felt that the pegasus could show a bit more appreciation to the young alicorn who had just filled her friend’s diaper with enough poop to be worth at least two good regular messings.
“But you do realize that this diaper isn’t so much ‘your’ messy diaper anymore is it?” Twilight couldn't help responding.

“Ha, ha. Ok, you’re right, thanks Twilight. Now, can you tape this up please, it…I want to feel it better.”

Smiling down at her friend Twilight again lifted Rainbow’s butt up a few centimeters above the diaper, and using her magic, -she was tempted to use her hoof directly for this task, but she had just gotten out of the shower after all- she began to smear the huge pile of warm gooey shit all over the inside of the diaper from the top of the front to half way up the back. It was oddly similar to the way she had seen Pinkie Pie use a knife to spread icing on a cake.

Having quickly completed this task she levitated the open shit smeared diaper, and in one swift motion folded it around and over the waiting pony’s butt and crotch, taping the four tapes tightly over the front and instantly coating everything inside the diaper in her gooey, runny poop.

Rainbow Dash let out a quite un-characteristic whimper of pleasure as she was lowered back down onto the bed and its protective clear plastic sheet. Her fore hooves immediately pressed themselves into the front of the diaper and her whimper became a groan. With Twilight’s mess so evenly spread out, no one place had enough of the stuff to easily squish out the leg holes or the top or back of the diaper no matter how Rainbow sat or laid or squished around. Even a good diaper humping wouldn’t produce much in the way of escaped mess. However, there was sufficient quantity that the areas around the leg holes would quickly, if they were not already, beginning to show an obvious spreading brown stain. An effect Twilight found rather sexy. At first glance all this effort of spreading her mess around evenly might seem like a peculiar manifestation of OCD, but in fact it had a quite practical purpose.

“So, it seems I’ve done my job to make up for your own body’s lack of results for this morning. I hope you enjoy my mess as much as you know how. It and your diaper deserve that much I think.” Twilight said, an edge of playfulness entering her voice.

“I guess this means I owe you one, doesn’t it.” Rainbow said, not really saying it as a question.

“Damn straight, you sexy mare.” Twilight said in a way that Cadance would be surprised by, but very proud of.

Dash’s eyes widened a bit but she broke out into laughter.

“I guess I’ll be seeing you again soon then won’t I.” She said, still smiling broadly up at the lavender alicorn.

“You bet!” Twilight said, smiling back.

****

Having packed her saddle bags to her satisfaction, a process that included the addition of the soaked diaper she has spent the night wearing, Twilight walked from the living room to the kitchen through a narrow door to find that the cottage’s owner had finally emerged, a bit drowsily, from her own downstairs bedroom, and that Rainbow Dash had apparently found her first.

Fluttershy was standing at the kitchen counter, in the process of fixing herself a small bowl of cereal. Her light pink mane and tail were a tad frizzy with strands sticking out a bit haphazardly here and there. Obviously the pony had only just gotten herself up out of bed. Twilight wondered if that had been all Fluttershy’s idea or if Rainbow Dash had come barging in on the poor pony and forced the issue. If the latter, she would have to give Dash a good lecturing about it. Fluttershy’s bed mane only served to add to her innocent appeal to Twilight’s eyes. Always the vulnerable seeming one, Fluttershy was. Though that appearance could be, Twilight had found on occasion, an uncommonly deceptive one.

Twilight’s eyes were quickly drawn to the sleepy mare’s appropriately adorable disposable diaper. It was extra thick, more so than either Rainbow’s or even Twilight’s. The diaper, bulky even when dry, positively bulged in all sorts of wonderful ways as it was absolutely drenched with pee. Very little of the originally bright white plastic surface of the diaper remained pristine. A double row of pink butterflies was printed on the slick surface, running from the top in front, around the tail hole, to the top in back. Now, an off white, slightly yellow color completely dominated. The diaper was very well made and taped on tightly, so despite being so heavy with pee, it hardly sagged at all. Twilight could imagine how so much warm urine being held so close against Fluttershy’s body must feel. The pony must have been wetting the diaper for over a full day to achieve this effect, it was not often Twilight had approached such an extreme state of total saturation.

That was probably why Fluttershy kept the thing on so long, Twilight thought, it must be a very comfortable and pleasurable sensation to be walking around or sleeping in such a thick, bulky mass of warm soaking wet plastic. Coming nearer, Twilight could see little droplets of pee trickling down Fluttershy’s back legs, leaving a trail of little spots on the hardwood floor wherever she walked. The pony seemed utterly unconcerned by the slight leaking, paying no attention to it. Twilight herself didn't enjoy a leaky diaper as it usually meant the diaper itself was of lower quality, and even if that was not the case, it still produced a mess to clean up wherever she had been. But on Fluttershy, the urine trickling down the mare’s hind legs was somehow…enticing.

Though, Twilight noted that an additional reason the diaper may be beginning to leak had more than just a little to do with how much pee it contained, seeing as how Rainbow Dash, who was standing behind and just to the side of Fluttershy was pressing a hoof into the bulky soaked padding below Fluttershy’s tail.

Grinning at Twilight as she entered the room, Rainbow Dash seemed to find the lavender alicorn a suitable audience to perform for, and escalated her activities by abandoning the hoof rub and mounting Fluttershy, diaper and all, like a stallion preparing to give the yellow mare a good rutting.

Twilight watched from the entry to the kitchen with a growing feeling of arousal as Rainbow Dash curled her forelegs about the base of Fluttershy’s wings, which were beginning to stretch out from her own increasing excitement, in the way of any aroused pegasus. Fluttershy lifted her tail up and to the side removing the last obstacle that would prevent their diapers from coming into full contact.

With a soft squeak of plastic on plastic the two ponies’ diapers pressed into one another, more drops of pee emerged from around the leg holes of Fluttershy’s diaper and the strong smell of Twilight’s own poop emerged even more powerfully from Rainbow Dash’s diaper. Twilight could see the cyan pony’s diaper was beginning to show signs of its mess-slicked insides as its color was changing from the light grey-yellow of a wet diaper to the grey brown of a very messy one. And the way that the wrinkles in the thick plastic surface of both ponies’ diapers around the tightly pulled tapes were shifting around as Rainbow Dash rhythmically humped Fluttershy’s diapered butt was really rather hypnotic.

Fluttershy’s wings were hard and stiff now, sticking nearly straight out to either side of her, an effect now being mirrored by Dash’s own wings. Fluttershy, cereal bowl quite forgotten, was keeping her front legs up on the counter top and sticking her backside out as much as she could, bending in a delightfully arched way to give Rainbow Dash the best round diaper butt possible to grind against. Apparently now quite uncaring as to whatever manner had been used to awaken her in the first place.

Twilight’s own pussy grew wet as she considered how her own slick poop was being smeared into every glistening fold and crevice of Rainbow’s pussy lips as the athletic pegasus slowly but firmly pressed her diapered crotch into Fluttershy’s padded butt. The continued slick rubbing sound of plastic on plastic of the diapers was wonderful all on its own.

The two pegasi seemed utterly lost in their own mutual world of diapered pleasure, Rainbow in her sleek and slick yet still thickly padded diaper full of borrowed poop, and Fluttershy in her more round and puffy diaper, absolutely bulging with multiple wettings.

‘What a perfect pair of friends.’ Twilight thought staring at the two of them.

Resisting the urge to retrieve her own wet diaper, now neatly folded up in her saddle bags back in the living room, Twilight fought down her desire to join in the fun and got herself her own bowl of cereal from the cabinet next to the sink. Though by no means did she ignore the performance of the two mares as they continued to find new and entertaining variations on the theme of pressing crotch against butt.

As Twilight progressed through her cereal, Rainbow became more and more insistent in her motions and as the last of the contents of Twilight’s bowl were eaten, Rainbow Dash came in her diapers with a judder and a groan, sliding her crotch up and down in long smooth movements over the roundness of the diapered butt she was bent over.
Twilight couldn’t help the heat in her cheeks, a companion to the heat still located between her back legs, as the two diapered mares joined her at the small round wooden table.

“Bet you liked that, didn't you Twi!” Rainbow said looking quite pleased with herself.

“I couldn’t help but notice who came first that time, in fact I don't think Fluttershy came at all.”

“Did you?” Twilight asked turning her attention to the yellow pony who had just sat on her chair slowly, savoring how the pee saturated padding of her diaper pressed itself against her.

“Um, no… not yet.” Fluttershy said looking down at the table top and not meeting Twilight’s gaze. Though the mare was smiling a bit as she spoke.

Rainbow managed to look almost offended.

“Fluttershy isn’t a pony I can really, I don't know, rush? I guess.” Rainbow said, trying to figure out how best to phrase her thoughts.

“I’ll make her cum today, I don’t give up that easily, but she will only cum when she’s been really horny for a long time, you know.”

“So in other words, you can never win with Fluttershy, she’ll always outlast you, so you don't even try.” Twilight said, smirking around a mouth full of cereal.

Rainbow scowled back at her.

“Now hold on, that's not what I meant, I- “

Dash cut off her rebuttal upon realizing Fluttershy was quietly giggling to herself, still not looking up at either of them.

As she and Twilight both turned to regard the shy pegasus, Fluttershy got up off her chair and walked over to Rainbow who was regarding her with curiosity.

“I just know you will try your best Dashi.” Fluttershy said quietly and gave the surprised pony a quick kiss on her cheek.

As she walked away from the table and towards the living room where Twilight had been before coming to look for some breakfast, Fluttershy paused in the doorway between the two rooms and spread her back legs slightly. Twilight watched as the pink maned mare grunted softly and the back of her thick, soaked diaper expanded outwards right under her raised tail with a faint sound unique to only one bodily function. Twilight realized that for Fluttershy’s extra thick diaper to have expanded so obviously in back, the mess the pony made must have been quite considerable in quantity.

“You know where to find me, Dashi” Fluttershy said turning her head to look back at Rainbow with a shy but surprisingly sultry smile.

With that she walked off into the living room and around the corner out of sight. A few seconds later the two ponies still in the kitchen heard her bedroom door open, then close with a soft click.

Rainbow looked at Twilight, grinning ear to ear.

“I think there’s something I need to do.” Rainbow said standing up quickly.

Briefly Twilight wondered if Rainbow’s pun had actually been intentional.

“Enjoy yourself Dashi, I’ll be back to see both of you late tonight. It looks like you will have plenty to keep you busy while I’m away!”

Rainbow Dash was already halfway to Fluttershy’s bedroom before Twilight finished speaking.