To Twilight’s surprise the next thing Rarity did was she began to untape her diaper. Rarity didn't give her any warning at all but suddenly Twilight felt a tugging on her front and as she watched Rarity’s blue tinted magic was slowly and methodically pulling the four fastening tapes off the front of her diaper. Twilight did note though that Rarity was doing so in such a way as to not damage the tapes at all potentially allowing them to be reused.

With a final pop the last tape came free and the front of Twilight’s diaper came loose. With a twinkle in her eyes Rarity stretched out a hoof and pulled forward on the top of the diaper. The front fell outward with a heavy plop as it landed on the plastic mattress cover. The sight that greeted the two ponies made Rarity gasp with delight and Twilight smile nervously.

Both the inside of the diaper and all the available space between Twilight’s legs was coated in a light brown glistening layer of slimy poop so thick that Twilight couldn’t even see her own marehood under it all. There also seemed to be another thin layer of clear liquid over much of the mess between her legs which was undoubtedly her just released mare cum. This made the whole collection of greasy filth shimmer in the lamp light.

“Oh Twilight I do believe that’s one of the most beautiful things I’ve ever seen.” Said Rarity with what seemed to be tears in her eyes.

The moment Twilight’s diaper was opened two new sensations swiftly occurred to her. The first was the admittedly very bad, yet somehow exciting, smell and the other was that without the diaper providing insulation the wet goo covering her suddenly felt quite cool. To be honest it was rather a pleasant feeling on an otherwise quite warm evening.

As Twilight was still trying to process her feelings Rarity reached out her hoof again and this time pressed it into the slimy coating right where she guessed Twilight’s marehood would be and started to gently push the brown mess away from her lower lips. Twilight tensed up at the sharp spike of pleasure at having a hoof tip move over her still quite sensitive area but that was nothing compared to the overwhelming ecstasy that knocked her back into the pillows behind her head when Rarity, a pony renown for her hatred of getting dirty outdoors plowed muzzle first into Twilight’s slick poop coated clit and began licking as deep inside it as she could reach.

Twilight, despite all efforts couldn’t keep herself from squirming all over the place, she even went so far as to reach around behind Rarity’s head and with a foreleg she pressed Rarity’s muzzle into her messy clit as hard as she could giving no thought on how the poor mare was supposed to breath under such circumstances. Yet Rarity expressed no apparent discomfort at this treatment and went right on making Twilight alternately whimper and cry out depending on what Rarity’s tongue was doing at the time.

Eventually the combined stimulation of her mess coupled with Rarity’s restless tongue proved too much for Twilight’s system to handle and with a couple swift convulsions of her back legs and hips Twilight came with a rather undignified yell into Rarity’s waiting mouth. Looking up at her partner for the night through half lidded eyes Twilight watched Rarity lift her head up from between Twilight’s legs showing her otherwise bright white teeth and cute lips coated with Twilight’s mess along with the new addition of a clear glossy fluid covering just about everything else.

Rarity, licking her lips, sat back down onto the bed in her diaper making a soft squishing sound and stared at Twilight fondly.

“Looks like my little pony has finally worn herself out for the night. Don’t worry about helping me with my needs for now; I can take care of that on my own. I think I’ve let you be exposed for long enough, its time to go back in your comfy diaper for the night. We wouldn't want you making a mess in the bed after all.”

With that Rarity’s horn began to glow and Twilight’s slick scat coated diaper tightly taped itself back up around her waist with a slight squelch. Twilight for her part simply shifted back deeper into the pillows as her still leaking slit was re-immersed into her comfortably cool squishy mess.

“Give me a minute to freshen up dear, I enjoy a mess in a diaper as much as the next pony but I can only take it on my face for so long!”

Rarity turned and sauntered off toward the bathroom giving Twilight plenty of opportunity to enjoy the thick diaper still holding tightly to her rump and refusing to sag despite its much-increased weight, the once perfect white color now beginning to turn slightly brown.

With the click of the bathroom door closing behind Rarity, Twilight turned back to stare out at the room. Her wings were still extended far out to either side of her, an unavoidable side effect of what her sensitive places had just experienced and to a certain degree were still experiencing. Now though, having had her sexual needs attended to Twilight became aware of a different sort of pressure that had built up between her legs. She contemplated letting it all go then and there but the sound of the bathroom door swinging open told her to be patient, at least for a bit.

Rarity sure was a master of cleaning herself up thought Twilight, looking at the white pony’s face now she never would have guessed how Rarity had appeared just minutes ago.

“Well now that’s taken care of.” Rarity said breezily, flipping her mane to the side with a shake of her head. “There is the matter of my needs, yes I know I said you don't have to bother with that and you still don’t need to do anything really but I would still like to um, ‘use you’ for my purposes if its quite alright.”

Twilight thought this wording odd but nodded her ascent. “Sure, Rarity, what ever you want. But first…” Twilight said motioning towards her diaper, “I thought you might like to... well, its just that I really have to go again.”

Rarity’s smile grew wide and almost a little predatory. “Dearest Twilight, were you thinking of me? Were you holding yourself back while waiting? You’re into this more than you like to admit I think.”

All Twilight could do was blush but Rarity was correct, as usual. Rarity hopped up onto the bed with surprising finesse for a mare with a thick messy diaper filling up the space between her thighs and immediately leaned forward with her face only inches from the bulk of Twilights own diaper. Rarity put out the tip of a forehoof and softly rubbed it over the front of Twilight’s diaper.

“Wet yourself for me Twilight, please? It would make me so happy to see you enjoy it.”

“Of-of course Rarity” Twilight said needing no real extra encouragement, the pressure was becoming quite uncomfortable after all.

Twilight released her hold on her bladder with a sigh and immediately her warm pee gushed out into the slimy poop coated padding. The force of her flow was too great for the now limited absorbency of her diaper to handle immediately, which made her urine splash back onto her still sensitive clitoris and lips before running down over her anus and pooling beneath her tail. In the process though it mixed with her mess turning it into a thick squishy soup, which she happily splashed her butt around in all the while still peeing forcefully. Eventually though her stream came to a stop letting the diaper finally catch up in its duty and the pool under her tail base was absorbed slowly into the already soaked and messy padding.

Rarity for her part looked to be in a trance of some sort gazing as intently at Twilight’s diaper as she was.

“Um, Rarity, I’m finished.” Said Twilight trying to get her friend’s attention.

“We-Well that was worth the wait! To be honest I’m almost envious, I don’t think I’ve ever seen another mare wet quite as beautifully as you do.” Said Rarity finally looking up.

“Seen another mare?…How many have you seen-“ Twilight was cut off with a hoof pressed to her lips.

“Never mind that for now.” Rarity said. “Perhaps I’ll tell you a few stories another day but for now it’s just you, me, and two very well ‘loved’ diapers.”

“Now you can’t expect a healthy young filly like myself to be able to watch what I just have and be able to get a good night’s rest without first attending to her needs do you? Rarity asked rhetorically.

“No, I guess not.” Twilight said smiling.

“Indeed not. Now just lie there and get comfortable, this shouldn't take too long.”

With that Rarity placed her right legs over the other side of Twilight, straddling her chest. She then gently lowered herself down until her diaper made contact with the soft fur of Twilight’s stomach and the continued lowering herself until all her weight was on Twilight’s middle with her tail extending back out between Twilight’s legs. Rarity’s sigh turned into a moan as her diaper squished audibly. Twilight noted that the areas around the leak guards of the leg openings on Rarity’s diaper had turned a dark brown. Perhaps Rarity had pooped in her diaper again? That would certainty explain her powerful reaction when sitting on her chest, the Alicorn thought. Rarity leaned forward slowly all the while making sure her diaper kept even contact with Twilight’s stomach. Despite the diaper’s bulk Twilight was certain she could see a thick pile of poop being forced between Rarity’s legs and up the front of her diaper. For a moment Twilight was worried that it would end up spilling out over the top making a huge mess she would have to clean up before going to bed, However she needn’t have worried as Rarity stopped leaning forward when her lips pressed into Twilight’s own.

Rarity’s kissing forced Twilight’s own mouth to open and she could faintly taste her own mess from when Rarity had buried her face into Twilight’s scat covered pussy. Though she had to admit it was actually Rarity’s breath that smelled worse for understandable reasons. None of this really mattered to Twilight as she was simply in heaven now that Rarity had begun to slide her diaper up and down the length of Twilight’s belly.

“You know…Twilight…sometimes it just…seems so right…to do this sort of thing… in a diaper. Let yourself get…messy in the…the front I mean. After…all our marehood is so…so close to where our…waste comes…from, doesn’t it make…sense that a filly might… at least every now…and again…get herself…rather dirty…in the course of…making herself feel…good?” Rarity asked while becoming increasingly energetic in her motions.

Twilight could see a number of ways a mare might disagree with Rarity on that point thought Twilight ruefully, yet Twilight could, oddly, see Rarity’s view on the matter. And after all who was she to argue considering she had spent the whole evening doing much the same as Rarity had.

Twilight also couldn’t help but note that with the way Rarity was pressing her messy diaper into Twilight’s midsection with such force that it was probably for the best that Twilight hadn’t eaten anything for a while. Otherwise she was sure, this experience would have become somewhat more uncomfortable.

With a final cry and a tight squeeze from Rarity’s thighs about her middle the white unicorn collapsed onto Twilight breathing hard.

“Mmm…that was wonderful Twilight, thank you…”said Rarity sleepily. “I really needed that after all he activities today. Well, since it’s already so late I was hoping you wouldn’t mind spending the night?” Rarity asked hopefully while sliding off Twilight to lay next to her on the bed.

“To be honest I was considering the same thing.” said Twilight.

“Oh how wonderful!” Said Rarity as her horn lit up turning off the lamp by the bedside and plunging the room into darkness.

“I’ll see you in the morning then Twilight.” Rarity said laying a foreleg over Twilight and pulling herself in tighter to the alicorn’s side, the front of her messy diaper squishing against Twilight's hip.

“Huh? Wait, but our diapers and-“ Twilight began, suddenly realizing that Rarity intended to simply fall asleep right then and there.

“What about them silly filly?” Asked Rarity with a touch of amusement in her voice. “There are few things more enjoyable in a pony’s life than getting a good nights rest while being comforted by the soft warmth of a thick messy diaper. Just relax in it and you will be asleep in no time, its very refreshing.” Besides, it’s late and I don’t want to deal with cleaning this up until morning. Rarity concluded.

Despite her initial shock Twilight could understand Rarity’s feelings. The slimy mess coating nearly everything under her diaper did feel oddly comforting as if its very presence meant that she was somewhere secure, somewhere she could experience such things of her own free will and where she could find the time to relax enough to spend the time to enjoy it and clean up properly afterwards without being rushed.

Twilight decided then that all things being equal there really was no good reason not to simply go to sleep and deal with whatever needed dealing with in the morning. Besides there was the fact that she had a rather hot mare in an equally well used diaper curled up so contentedly by her side. After all, what kind of friend would Twilight be if she disturbed such a scene of serenity?

As Twilight began to drift off to sleep in the warm embrace of her dirty diaper she heard a faint sound like a soft hissing coming from the vicinity of Rarity’s diaper. Twilight smiled to herself as she snuggled deeper into the pillows. Rarity’s wetting was beginning to become one of her favorite sounds.

***************************************************************

Twilight awoke laying on her left side her form illuminated by the diffuse sunlight streaming through the curtains of the large east-facing window. At first her mind simply drifted with little awareness of her physical form at all, only dimly acknowledging the plastic protected mattress she rested on. Before long though the presence of something warm and…squishy surrounding her crotch and butt made her look down at herself. She was greeted with the sight of her full disposable diaper who’s outer plastic layer, once a light violet now appeared slightly brownish from the stained padding underneath. The image printed on the front of the diaper of the famous Canterlot model Flur looked out at her as happily as ever.

Twilight smiled to herself as the memories from the day before filtered in to her waking mind. Rarity was right, sleeping in a well used diaper was a great experience, even better when that experience could be shared.

“Good morning Rarity.” Twilight said stretching her legs out and rolling onto her back “Thank you for- oh….” There was no Rarity to thank apparently. Twilight suddenly found herself alone in the bed. Though now that Twilight was paying attention the sound of running water coming from the bathroom might well explain Rarity’s absence.

Lacking any better ideas for what to do while waiting for Rarity to come out Twilight simply decided to enjoy her diaper, it was why she was still here after all. Though having lost interest in staying in the bed by this point Twilight got up on her hooves and gently hopped off the red and white patterned mattress. The young Alicorn simply trotted around the room idly examining her surroundings while enjoying the way her still securely fastened diaper squished around her sensitive parts and rump. She had been wearing the thing constantly for over twelve hours by now she was sure, with it being wet and messy for most of that period. The diaper was beginning to smell quite bad which didn't really bother her, she was slightly concerned though that having her mess in direct contact with so much sensitive skin might not be for the best over long periods. She figured being an Alicorn may help with that, though Rarity for her part hadn’t seemed to worry about any discomfort.

As Twilight continued to wait for Rarity she soon felt the need to go, a common thing for her in the mornings. Might as well, Twilight thought, it won’t make things any worse and besides I’m going to be out of this diaper soon enough. Without pausing to give it any more consideration than that she simply spread her back legs and pushed. Twilight was immediately rewarded with a hot pile of squishy poop spilling out of her into the back of the diaper mixing with the mess from the day before. It really was wonderful just being able to go in a diaper like that. There were so many pleasant sensations a pony missed out on by simply using the toilet. There was one more thing Twilight could do to make it feel even better though. She hopped up onto the bed where she laid down on her back then slowly rose into a seated position with her back legs sticking out over the edge of the bed. This process squished the new mound of somewhat runny poop straight between her legs and up the front of the diaper. Twilight sighed basking in the new sticky warmth spreading around her marehood. At that moment it was difficult for Twilight to imagine anything at all which could feel better. This is what wearing a diaper is all about thought Twilight, pressing a hoof into the front of her completely full diaper it just-

“You wound me Twilight! Going off and having fun without me like that? How insensitive!” Rarity said now with a coat as fresh and sparkling as always standing in front of the now open bathroom door.

Twilight for her part quite nearly fell off the bed.

“Gha! S-sorry, I was just waiting for-“

“Oh Twilight, I was simply teasing you, here now, as good as it looks on you I believe you've been in that diaper long enough. You’re of course welcome to use my bathroom here to freshen up for the day.”

“Right yes, I should clean up as soon as possible, can’t go around town like this now can I, haha” Twilight laughed nervously.

The Alicorn princess rounded the bed and stepped into the surprisingly spacious bathroom given the overall size of the boutique’s smaller upper floor. She couldn’t help noticing the way Rarity’s eyes followed her movements in a way that made Twilight quite certain that if Rarity could come up with a good excuse to keep her in diapers she probably would have. Unfortunately for the unicorn Twilight couldn’t stay in that place forever. Spike would probably begin wondering where she had gone off to this time and there was her upcoming trip to Canterlot that required preparation.

“Hey Rarity?” Twilight called out from the bathroom. What would you like me to do with my diaper? She asked realizing that she had no idea what Rarity had done with hers and seeing no convenient place to dispose of her own.

“Don’t worry about it, just leave it on the floor to the side there and I’ll deal with it after you’re finished in the shower.” Rarity replied back from somewhere out in the bedroom.

Odd, thought Twilight, it wasn’t like Rarity to let another pony leave a mess out in a room. Then again little that Twilight had seen the pony do over the last day had fit in with her preconceptions of Rarity’s private life.

“Oh, ok.” Twilight replied back already working at the tapes with her magic.

Though still securely fastened they held little resistance against a concentrated magical force and they soon all poped free.

Twilight then levitated the diaper over to the side out of the way under the sink. She found herself being rather amazed while looking at the thing. The inside was completely coated in her filth and the whole diaper was swollen with her fluids.
The clear comprehension that she had not only been wearing such a wonderfully disgusting thing but had actually spent an entire night’s sleep in it made her rather hot. Though this was not a time to get involved with another self-pleasuring session. She was beginning to want to get home and the sooner she cleaned herself up the sooner she could be on her way.

She began in the most direct and effective way she knew how, with a glow surrounding her horn Twilight pushed her magic against her lower body and using it like an unnaturally effective squeegee she removed the vast majority of her mess out of her fur and into a slimy brown ball floating in the air. For a second she wasn’t sure what to do with it. The obvious choice would be the toilet but that seemed like a waste somehow. No, why not simply put it in her old diaper with the rest of it. It seemed fitting somehow as she squished the ball of poop in with that sill in the diaper. Twilight giggled a bit as she spread it around with her magic.

Though her magic had taken care of the vast majority of the problem it hadn’t done much about the rather overpowering smell or the fact that much of the fur around her hindquarters was now slightly stained. One way or another she was sure that Rarity had plenty of ways of dealing with this exact situation. A quick glance into the bathing area complete with shower told her that she had been more than correct about her assumption when she found well over a dozen varieties of shampoos, conditioners, and scented soaps. Despite her desire to get home soon Twilight decided that no matter what, she was going to take the time to enjoy this process, it was after all a bit overdue upon consideration.

**********************************************************************************

Stepping out of the bathroom, mane wrapped up in a towel and followed by a small cloud of steam Twilight once again found herself alone with no Rarity in sight. Probably went downstairs to get to work on something or other, Twilight thought.

After having the diaper on for so long it actually felt a bit strange to not feel it around her, and this feeling of absence reminded her that the diaper in question was still on the floor of the bathroom where she had left it. Even though it made the bathroom smell unpleasant Twilight had no obvious options other that to simply go along with what Rarity had said and leave it alone. Though for fear of the smell permeating the bedroom as well Twilight opened the large curtained window on the west side of the room before making her way down the stairs to the main floor.

Despite her wanting to get home Twilight made an effort to find Rarity to thank her for the strange but wonderful, and it should be said enlightening, overnight stay. However as it turned out Rarity was had further plans for Twilight.

“There you are Twilight, would you be a dear and take this by Sugar Cube Corner on your way.” It’s going to be a busy day for me but Pinkie Pie is really looking forward to this delivery.” Rarity said emerging from one of the back rooms with a saddlebag held in the air with her magic.

“A delivery…?” Twilight repeated, her mental train having been momentarily derailed by the unusual request. After all most of what Rarity sold were dresses, and Pinkie Pie had hardly ever worn thoes. Furthermore Rarity didn't make a habit of having her friends deliver things for her.

“Yes, dear, a delivery.” Rarity said smiling. “Please, for me?”

Twilight really couldn’t come up with a good reason to deny the request, besides it wasn’t as if it would take her much out of her way. So with a slight inward sigh and an outward smile, she answered in the affirmative.

“Oh thank you! You really are a good friend!” I hope so, Twilight thought to herself considering her official title.

Before opening the front door to let Twilight out Rarity stretched out her head and gave Twilight a soft kiss on her lips. “I mean what I said, Twilight, you are a good friend, as good a one as a mare could wish for.” Rarity said stroking circles around Twilight’s cutie mark. If you ever want to come by for some company I would love to have you over here” I do sometimes get lonely by myself you know, Applejack isn’t always around and…” Twilight’s heart softened for her old friend, she was perfectly aware of Rarity’s implications but chose not to directly reference them.

“Of course Rarity, I’d love to give you some company, it would be my pleasure.” Twilight couldn’t help but return the kiss along with her reply. As their lips parted Twilight swung the door open with her magic and stepped outside into the bright early afternoon sunshine.

“See you later Twilight! Oh and tell Pinkie Pie that I expect to be repaid in the future.” Rarity called as she closed the door.

The alicorn couldn't help but blush at the thoughts that came to her mind, unbidden, as to precisely how it was Rarity surely meant to get her 'repayment'. Perhaps if she was lucky enough she might be allowed to be invited for the fun, but that was a project for another day.

As Twilight wandered her way closer into the center of Ponyville the number of ponies steadily increased. Due to it being a Sunday many ponies were simply out enjoying their day off and incidentally the nice weather. There was Lyra and Bonbon laying next to each other in the grass reading what looked like a magazine of some sort and a group of fillies were playing in the small shallow stream that wound its way through the town. It all rather made Twilight feel bad for Rarity who insisted on cooping herself up in her place of business to continue her work instead of taking a break like most ponies. Well there was not much hope of changing that behavior any time soon considered Twilight. Rarity loved her work and there was no separating her from it.

Some of the ponies gave Twilight sideways glances as it was unusual to see the Princess of Friendship walking around town with a pair of saddlebags and ones with Rarity’s cutie marks printed on them no less. Twilight resolved to not show any embarrassment and continue on her way as though nothing was out of the ordinary in the least.

At last the Alicorn came upon Sugar Cube Corner, the most successful bakery in town and where her good friend Pinkie Pie was a live-in assistant. The large two story red and white building never failed to feel warm and inviting. Twilight hurried up her pace eager to get on with things and drop of the saddlebags and whatever it was they contained so as to not attract anymore attention. Or rather no more than was normal for an Alicorn of her social standing.

With a ringing door bell Twilight stepped into the well stocked establishment despite the “closed” sign on the door which given her familiarity with the shop’s owners and staff she could generally ignore at will. The front showroom was ringed with cases full of cakes and pastries which lined every wall and a large counter in front for serving the many customers which could be expected on any given weekday.

Before Twilight could make her presence known to the seemingly empty bakery beyond the sound of the doorbell a loud “Up heeeere!!” came from upstairs.

Well let’s see what this is all about then. Twilight thought to herself starting for the stairs.