"Anon," says Celestia, staring down at you with a grin, "So good of you to respond promptly to my summons."

"Summons?" you say, sitting upright. "I didn't get a summons, Twilight just fucking teleported me here from my bed."

"The details aren't important," says Celestia. "What matters is, I wanted you here, and here you are."

"What time is it?" you ask, squinting your eyes. You look out the window and see a starry sky. "Fuck me, who wakes up this early?"

Celestia chuckles softly. "Ponies with responsibilities," she says. "Like raising the sun."

"Oh," you say. "You wanted me to watch you raise the sun?"

"Sort of," she says. She begins to circle you, eyeing your body, nudging you here and there with her muzzle. You twist your body to try and avoid her, but you're cautious about putting up too much resistance - you've never bought Celestia's benevolence act. You're also a little leery of coming into contact with her big horse dick, which is creeping menacingly out of its sheath. You've come to accept that the ruler of Equestria is a princess with a big fat cock, but accepting it doesn't mean you want to touch it.

"Anon," she says, "Did you know that raising the sun is quite a strain... but also rather enjoyable?" You mumble noncommittally, and Celestia continues. "You see, Anon, I find myself wishing that I could... let loose when the feeling comes over me. And I'd like your help with that."

"What exactly are you asking me for, Sunbutt?"

Celestia giggles. "Oh Anon, you're so fond of that nickname. Some royals would be offended by such an appellation. Personally, I take it as a compliment that such a handsome creature as yourself has taken an interest in my rump." She bumps you with her rear, knocking you off balance with her considerable mass. "And I have an idea as to how you could get better acquainted with it."

"Woah," you say, backing away. "I may have given you the wrong idea..."

"Don't be shy, Anon," says Celestia, her voice becoming more seductive with each word, "Don't you know it's an honor to serve your Princess, even in the most humble of roles? And I have a role you're perfect for. Or at least... you will be..."

Her horn glows the color of sunlight, and her magic envelops you. You feel paralyzed, immobile, and your extremities grow numb... then seem to disappear entirely. You try to speak, but you can't move your mouth. You feel like you don't have a mouth, actually.

"Ah, you look wonderful, Anon," says Celestia. You're lying on the floor, totally immobile, and she's staring down at you again. "How do you feel?"

You try to speak, and Celestia gives you a quizzical look. "Oh," she says, "Let me establish a mental link, so that you can speak to me with your mind."

You focus your thoughts at Celestia, and mentally ask the horse bitch what the fuck she thinks she's doing.

"You can't tell?" she says. "I suppose it's an unfamiliar feeling. You, my little human, have become a diaper. A Princess-sized diaper with a little logo on the side... ah, I see. It's a question mark in a green circle, just as one might expect."

"You turned me into a diaper?" you say, though the mental link. "What kind of sick shit are you planning?"

"Oh, don't rush to judgment, Anon," says the Princess. "You might enjoy this experience more than you expect." Her magic envelops you, and you feel yourself being wrapped around her ample ass. The sensation of your soft diaper body being wrapped around her ass is actually enjoyable; the feeling of her half-hard cock pressing into your front is less enjoyable.

"You see, Anon," says Celestia, "Moving the sun puts a unique sort of strain on me. My body begins to yearn for release... in more ways than one. There's an indescribable buildup in both my royal bowels and my majestic cock. From time to time I indulge myself, but... oh Anon, regular diapers just don't do the trick! Only a magical diaper, created from a transformed creature, has the power to contain my loads."

"Then why me?" you ask.

Celestia sighed. "I have complicated feeling towards you, Anon. You don't respect me, and you're such a bother, but I can't stop thinking about you. I want to keep you close... but I also want to punish your unforgivable insolence..."

She begins to rub her hips against each other, making your body bunch up underneath her. Her cock grows, and the flared head pushes against your insides, dripping a bead of precum into you. To your surprise, you can taste it, all salty and musky.

"I can taste your cum..." you say, then a realization hits you. "Oh God, you're going to shit in me too!"

"Calm yourself, Anon. Have you ever observed a pony defecating?"

"No!" you say, "Why would I?"

"Well, if you had," says Celestia patiently, "You'd know that, unlike your species' foul excreta, ponies produce food. Fully edible, oftentimes delicious."

"You're shitting me."

"Not yet I'm not," she says. "But when I do, I think you'll be pleasantly surprised. Hmm, why don't I get started? My little ponies deserve a prompt sunrise, don't you think?"

You protest, but Celestia is undeterred. She parts her legs slightly, and her body tenses. She must be raising the sun; you can still see, somehow, but you're facing away from the window and you don't have a view of the eastern horizon. Her cock is growing inside you, drooling musky pre as it pokes further and further into your diaper body. There's movement in her backside, heralding the arrival of the sun princess' dump.

"Here it comes," says Celestia. "I'm going to... fill you with my poop!"

Her asscheeks part, and the head of a thick turd pokes against you, You can't help but taste it, and you're expecting it to be foul... but Celestia wasn't lying. It's sweet, and it has a thick texture you recognize...

"Are you pooping brownies?"

"Blondies, actually," said Celestia. "Similar to brownies, but made without chocolate. Brown sugar will be the dominant flavor, and... mmm... if you could chew, you'd notice toffee chips."

The turd pushes its way out of her ass and curls against your inner surface. Sure enough, your "taste buds" fill with sweet brown sugar. "You sure know your poop," you say, resigned to your fate.

"Of course I do, Anon. It's important to know what I'm sharing with my favorite human. And - ooh - if you want a princess to poop brownies into you, perhaps I can lend you to Luna sometime. I'm sure she would love a magical diaper to hold all of her shit and cum while she raises the moon..."

"What?" you shout, as the first footlong food-turd breaks off and settles inside you. "I'm not doing this again!"

"No?" says Celestia playfully. "I don't see how you have - ooh, ooh - much of a choice in the matter, my sweet little diaper. I can do this to you - mmff - whenever I want." She begins to push harder, and her thick, sweet shit pours into you, making your material crinkle and bulge.

You're about to voice another protest, but Celestia interrupts you thought process. "Oh, here it comes! Get ready for my sweet princess cum, Anon!"

The head of her marecock is already pressed against your insides, and when she spurts, her cum is thick as frosting, splattering forcefully against you. Spurt after furious spurt of jizz fills the front of you, and the taste of her sweet poop is joined by the musky, salty flavor of her cum. The volume of her orgasm is frankly scary; even if you were human, your body would still be bulging if she'd cum inside you.

Your body sags with the weight of Celestia's poop, and her cum pools thickly at the bottom as her orgasm dribbles out of her. "I'm sorry, Anon," she says, "I lied - my jizz isn't sweet. It's just horse cum." You don't feel like admitting it, but there is something nice about the way the salty and sweet flavors of her cum and shit mingle inside you. "So how does it feel?" she asks. "Now that you're fat and bulging with my royal seed and my sweet, tasty shit... do you love being a diaper on my big fat sun-butt?"

If you're being honest, it's not nearly as bad as you were expecting. But you're not about to admit that. "Whatever," you say. "Can you just turn me back to normal and let me get back to sleep?"

"You want to go back to sleep?" asks Celestia. "But your job isn't done, Anon. I've got a full day of cumming and shitting ahead of me, and so do you."

"What do you mean? I'm full!"

"Full?" she teases. "Not nearly. You're a magical diaper, my dear. You might feel full, but trust me, you've got a lot more growing to do."

"So you're just going to keep a diaper on all day?" you say, "Won't your subjects... notice?"

"I should hope so," says Celestia. You feel her legs moving, shifting around the sticky, sweet mess inside you, and she begins to move towards the door of her bedchamber. "My staff would be terribly unobservant if they failed to notice a messy diaper on their princess." She chuckles. "You assume there's something shameful about what I'm doing, Anon. But I've done it before, and no one tells a princess what to do with her royal mess."

Celestia's first stop is breakfast. Since your "eyes" are on the back of your diaper-body, she turns herself around so that you can see the spread on her dining table. It's a dismayingly large breakfast - pancakes piled high, racks of toast, a selection of pastries... everything an alicorn needs to start her day. "Mmm, I'm going to enjoy this," she says, "And then a little bit later... you're going to enjoy it." And then she farts, blowing brown-sugar-scented gas into you.

Celestia's assistants approach as she eats, presenting her with routine business. Between thoughtful bites, she gives her approval, or she doesn't. She arranges meetings or cancels them. And all the while, she farts loudly and proudly into you, eliciting no reaction from her staff. It seems they really are accustomed to seeing her in a messy diaper, relieving herself without shame.

"Mmm," she says, wiggling her butt in her seat, smushing her mess around inside you, "Nothing like a nice big breakfast... and in a few hours, a nice big lunch for my wonderful diaper."

Later in the morning, Celestia holds court. The throne room is lined up with normal citizens, all of whom are too polite, or too cowed, to mention the messy diaper that Celestia's ass is resting upon. With little else to do, you listen to the pleas of the ponies. Celestia listens too, and responds with sympathy and wisdom. As skeptical as you've been about Sunbutt's benevolence, she genuinely does seem to be a good ruler...

"Just a moment, my little ponies," she says, after hearing from a couple dozen citizens, "My breakfast has made its way through my system, and it's time to feed my poor neglected diaper a load of shit."

Never mind, you think to yourself. Sunbutt sucks.

"It may interest you all to know," she says casually, as a long fart signals the start of her dump, "That my diaper is actually a magically transformed creature. Would you like to know who I turned into a diaper?" Her dick starts to grow.

"What the fuck?" you yell, through the mental link. "Don't tell them!"

"I'm sure most of you know about 'Anonymous,'" she says, ignoring your objection. "Or 'Anon' for short. The grumpy little malcontent of a human. This morning, I turned him into a diaper, so that I could punish his disrespect and bad attitude by filling him with jizz and shit." She grunts, and a fat blondie log slides out of her ass, joining the lumpy mess inside you. "But to tell you the truth, my little ponies, I think he's actually enjoying it. I think he might beg me to keep him like this."

"She's lying!" you shout. "This is slander!" But no one other than Celestia can hear you.

"I think it's my poop that he loves so much," she says. "Maybe it would be a better punishment if I came inside him again. Maybe a load of my salty cum will show him the error of his ways."

There's movement around the shaft of her cock - you can't see it, but she must be using her magic to jerk herself off. "Oh," she moans, "My little ponies, I want you to watch me punish my insolent diaper with a thick load of pony princess cum." The motion around her cock becomes faster and faster, and she begins to move her hips inside you. Another thick log of brown-sugar turd presses into you, and a third follows right after it. Her cock pulses, and her cum shoots against your insides again, flooding your sense of taste with a fresh load of musky jizz. Once again, you actually find yourself appreciating the mingled taste of her sugary scat and her salty cum. But you can never, ever let her know that.

"Ahh," says Celestia, releasing a final lump of blondie-shit and a bassy fart into you. She wiggles her rump, squishing the enormous mess beneath her. Incredibly, your diaper body seems entirely capable of holding it all - there's no leaks, even as she smushes it around. "I think Anon is properly punished for now. Or rewarded, depending on how much he enjoys what I've done to him..."

With that done, she sees the rest of the citizens, none of whom seem especially put off by what they'd just seen. A couple of them, on their way out of the throne room, actually say goodbye to you, which is pretty humiliating.

"Well, my big messy diaper," says Celestia, standing from her throne. "I think it's time I had a nice... big... lunch."

Today's lunch, like breakfast, is a mostly private affair. It's also a gigantic meal that threatens - nay, promises - to become a massive load of dessert-shit in a few hours. Assistants come and go throughout the meal, bringing more business to the princess' attention. Your attention fades in and out - you find yourself focusing on the feeling of fullness inside your diaper body. Being so thoroughly overstuffed with Celestia's shit and cum actually feels good, like the feeling of having a satisfying meal in your belly. And since you still taste with your insides, the flavor of her sweet, lumpy shit and musky seed is perpetually in your "mouth."

You're forced to admit to yourself that being a diaper is actually nice. It's relaxing, Celestia's poop is delicious, and the humiliation... it's kind of a turn-on. If you didn't have your pride to think about, you actually would be okay with doing this again.

The time between lunch and dinner is fairly uneventful - just a few minor meetings, and a walk around the royal gardens. As Celestia takes her constitutional, your sagging diaper body swings underneath her. Your lumpy mass hangs almost down to her knees, and the motion of her hips inside you fills you with an nearly erotic sensation - but there seems to be no way for you to cum, so it builds and builds inside you, never finding release. Celestia teases you throughout the day, threatening to release another load into you - but each time, she just lets loose another big, sugary fart.

Finally dinner arrives - and it's an enormous, well-attended banquet in the castle's main dining hall. Of course it is. Celestia goes from table to table, greeting dignitaries and prominent citizens, introducing you as "Anon, the big messy diaper" and answering follow-up questions about your transformation and how much you love it when she cums and poops inside of you. You try to protest, but after several groups of ponies fail to hear you, you quiet down and let Celestia sow the seeds of your humiliation.

Finally, the princess takes her place at the head of the main table. As her body turns, you get a chance to scan the room. There's no one here you recognize, which isn't especially surprising - most of the ponies you know live back in Ponyville. If you're going to be publicly humiliated, at least it's in front of a crowd of strangers.

"Fillies and gentlecolts," begins Celestia, and then she launches into her prepared speech, praising the civic-mindedness and generosity of the ponies present. The banquet was about... education, maybe? Commerce? You sort of tune it out.

"And finally," she says, "We have a special guest with us. Some time ago, Equestria received a visitor named Anonymous, a "human" from beyond the known world. Many of you have heard of him... fewer, I suspect, have become acquainted with his persistently negative outlook and troublesome behavior. As a princess of this land, it falls to me to correct his behavior. As a disciplinary measure, I have transformed him into this big, handsome diaper you see strapped to my royal butt."

"I've spent the day filling him with my shit and cum, which has resulted in the sagging mess you see here. I'm not sure he's learned his lesson, though... I've come to suspect that he actually enjoys in when I poop in him and shoot my thick princess cum into his crinkly diaper body."

"But as long as he's still a diaper... why don't I try one more time to discipline him with my royal seed and my sweet, tasty turds?" The audience stomps its hooves and cheers, with what sounds like genuine enthusiasm. Celestia turns, so that your "eyes" are facing the audience and their eager smiles. God, why are they so into this?

Celestia grunts and lowers her butt, smushing the heavy mess inside you down into the floor. She grinds you into the floor, smearing the sugary, musky mess inside of you, and her dick grows out of her sheath, poking into your insides. She begins to jerk herself off magically, and the head of a turd pokes out of her asshole.

"Oh, he loves it!" Celestia calls out, her voice resounding through the banquet hall. "He loves it when I feed him my thick, sugary shit! Oh, he wants to be bigger! He wants to be full and fat and bulging with my poop!"

She jerks herself off faster, as thick logs pour out of her ass. Your own arousal is building too - you don't understand where it's coming from, since you don't have a human body, but you feel like you're somehow close to coming. Your diaper body bulges fatter and fatter as her mess grows, and you sag further and further down, still holding in every ounce of her brown sugar shit.

"Oh, I'm going to cum, fillies and gentlecolts!" cries Celestia, gasping for breath. "I'm going to soak this naughty diaper with my thick salty cum!" Crackling farts billow against your insides, and a single, thick turd presses against you, filling your senses with the brown-sugar flavor of her blondie poop. Then she cums, shooting thick ropes of jizz into you at a velocity that's almost painful. The presence of the crowd seems to be a turn-on for her, because she's coming harder than ever before, mingling an unthinkable volume of princess cum with the delicious poop that's already filling you up.

And somehow, you cum too, the climax shooting through your bulging, shit-filled body. You cry out through the mental link with Celestia, and she moans in orgasm right along with you, filling the hall with her outcry. Finally, she slumps to the ground, and your sagging body, filled with sticky mess, settles on the floor.

"So are we done here?" you ask, as Celestia closes the door to her bedchamber behind her. "Or are you going to shit out that big dinner into me before bed?"

"No," says Celestia, "That dump is for tomorrow morning. I'll turn you back to normal now."

She magically removes you and tapes you up, holding up your diaper body and the massive, lumpy mess within. You feel your body go numb for a moment, and then your limbs and your mouth are back - along with the rest of you.

But the feeling of fullness is still there. Your pat your bloated, naked belly and look accusingly at Celestia. "Is all that still in me?" you ask.

"You mean my shit and my cum, Anon?" says Celestia, looking at you with amusement. "Of course it's still inside you. Where else would it be?"

"Ugh, whatever," you say. The feeling of fullness, to your dismay, is still surprisingly pleasant - you'd prefer to remember this as an unpleasant experience, and it's hard to do that when so many parts of it are so enjoyable. "Just send me back home and please never do this again."

"You didn't enjoy being my diaper, Anon? Is that what you're saying?" You shoot her a dirty look, and she continues. "I don't think you're being honest with me. You see, our mental link shared more than just your conscious thoughts. I was able to sense the pleasure you felt as I filled you with my poop and my jizz. Even through all the shame, you loved being my big, fat, messy diaper."

You try to glare at Celestia, but you can feel the blood draining from your face. She knows. "You should be more honest with yourself about the things you enjoy, Anon. And if I'm going to teach you that lesson... I think you'll need to do this again.

You sigh. There's no arguing with a magical princess. "So... what, then? We're doing this again tomorrow?"

Celestia raises an eyebrow. "Why wait til tomorrow?" she says, as her horn begins to glow. "My sister should waking up soon, and I'm sure she would have just as much fun with you as I did..."