It was a cool autumn afternoon in Ponyville and the clouds above had just parted ways to conclude the gentle rain that had dampened the thirsty ground below. The cool, misty air served as the perfect backdrop for Fluttershy’s famous tea parties. It was often a small guest list, usually just including her best friends. She never did care for large parties. Especially when she was the one hosting. Discord was invited, as per usual, but things very quickly went into a different direction.

“Phew! What a stinky girl!” Discord cooed at Fluttershy as he kept her thoroughly engaged with playful tummy tickles. “Are you already in need of a changee?”

Fluttershy just giggled, content to just wiggle and squirm under Discord’s relentless tickling claws. The pegasus was the epitome of bliss and innocence. She was just so overjoyed to play with her toys and having Discord there made it all the more fun. There might have been a time earlier that day where she was fussing over the details of her tea party, making sure everything was just perfect for all her friends. But that was in the past now. All that seemed to float around in the foal minded pony’s head now were happy thoughts. Simply, happy, floaty thoughts.

Discord smiled at the happy mare as she babbled and played to her heart's content. It seemed like no matter how much she played and rolled around, her diapers stayed on snug. They seemed to have been just the perfect fit for her little playtime. He had them specially made for their little playdate and he was glad to see they were so absorbent. Seeing the cutie marks of her friends on them just seemed to be icing on the cake for Discord as he reveled in taping her into each one.

“Looks like that’s the last of your diapers,” Discord commented, eyeing the empty shelf where a small stack of diapers once sat. Fluttershy just giggled, undeterred by Discord’s silly teasings. “What do you say after lunch we head out and do a little shopping?” Discord asked the regressed pony, tickling under her chin ever so gently. “I’m sure you won’t mind wearing a stinky diaper for just a little longer.”

Suddenly there was a knock at the door, interrupting an otherwise carefree and relaxing playdate. “Now who could that be?” Discord chimed, giving Fluttershy’s soft belly one final pat before floating over to the front door.

The wooden door was opened to reveal Rainbow Dash, Fluttershy’s fast moving, athletic pegasus friend. She always had a knack for being pushy, nosy, and often times brash. Discord found it easy to rile her up. Keeping Fluttershy far from view, Discord welcomed the unwelcomed guest with his usual theatrical flare.

“Why Rainbow Dash! Tis truly a pleasure!” Discord exclaimed with a deep dramatic bow, “what brings you here on such a lovely day?”

All too used to Discord’s exuberant personality, Dash was quick to cut through it and go straight to business. “Is Fluttershy home?” she asked, trying to crane her neck around the much larger draconequus “I can’t find any of my friends anywhere...”

Discord’s eyes lit up as a fiendish plan began to form. A perfect fate to such a nosy little pony. “Sure, she’s right in here,” he led the blue pegasus in with a wave of his hand, “come on in.” He opened the door all the way, revealing the living room in all its glory.

The living room had been adapted into a makeshift playroom for Fluttershy. A playmat was spread out in the middle, giving toddling ponies a soft place to roll around on without hurting themselves. An open crate of toys sat in the center of a sprawling pile of brightly colored baby toys from plastic blocks to teething rings. Close by was a diaper pail, for when the inevitable diaper change came along. And smack dab in the middle of it all, flashing her brown stained diaper bearing Rarity’s cutie mark on its rump, was Fluttershy herself.

“What...what is...” Dash was bewildered by it all. All these childish toys laid messily across Fluttershy’s house. Her best friend babbling like a foal while drooling over herself. The ever present stench of old diapers looming just in the background of her senses. She charged into the room, stopping right in front of the regressed pegasus. “Fluttershy! What’s going on?!”

The yellow pegasus looked up from her colorful toys, recognizing her name among the other words that were gibberish to her. Her eyes lit up with a big, bright smile as she happily babbled something that resembled a squealing greeting. She bounced on top her messy diaper bottom, overly ecstatic to see one of her best friends had come to visit.

“Look at that, Rainbow Dash, she remembers you!” Discord grinned from over Dash’s shoulder, “I bet she’s so excited for her diapee change.”

Like magic, the mention of the diapers made Rainbow Dash’s eyes lower to the crinkling garment that her friend wore. The diaper was thoroughly used and by the looks of things had been for quite awhile. There was hardly a place on its plastic covered shell that wasn’t covered in a dingy yellow or a murky brown. It drew a lot of attention to itself, especially the trio of blue diamonds that decorated the front panel of the diaper.

“What have you done, Discord?” Dash asked, struggling to pull herself away from the horrid sight.

“Entertaining,” Discord simply said, smirking smugly at the stunned pony. “It’s all a bit of fun, my little Dashie. You wouldn’t believe how much fun we’ve been having!”

“We?” Dash repeated. Somehow she got the feeling he wasn’t just talking about him and Fluttershy.

A devilish grin grew on Discord’s mouth as he waved a glowing hand into the air. Conducted by his levitating magics, the nearby diaper pail floated over to the pair, opening itself up to reveal its overpowering and pungent contents. Piled inside were rolled up diapers, each one bearing the cutie mark of one of Rainbow Dash’s friends. By the smell of things, some of the diapers in there were a couple days old.

“Each one of your little friends,” Discord commentated on Dash’s horror, “and each and every one of them our little stinker over there has used up one after the other. I must say, I never expected a baby to go through so many diapers!”

Dash could only stare at the disgusting sight in shocked revulsion. It was just too unbelievable to look away from. A pile of diapers apparently worn and used by her friend Fluttershy. For the faintest second, she could have sworn she saw a pony’s face fading into existence on the front panel of the diapers. For that brief moment, she could have sworn she saw her friends.

“Fix it!” She demanded.

“Oh I plan to,” Discord grinned smugly as he leaned forward until his eye level matched Dash’s. He raised but a single, clawed finger, drawing attention to talons that glowed with a fiendish, multi-colored aura. He then tapped Dash’s nose with the single claw, seemingly doing nothing but send a bolt of static electricity down Dash’s snout. If she only knew what sort of magics were twisting through her body, swarming through her insides faster than the eye could see.

The first thing to go was her motor skills. She immediately lost the strength in her legs, causing her to slide to the ground, splayed out in spreadeagled on the floor. Her body tingled all over as the very muscles in her body softened and lost their tension. Her glorious rainbow colored tail and mane melted into a desaturated mess, shortly followed by the rest of her body losing its cyan glow. Her bones softened with her muscles as she felt her body painlessly fill up with a soft padded filling. Her skin and coat, now a pale blue with only her cutie mark remaining in its original, vibrant glory, melted into a thin, crinkling plastic.

“Now no more squirming. This’ll be over in no time,” Discord so casually stated, smiling devilishly at the melting pony, “don’t worry, you’ll be finished soon.”

Dash’s mouth melted together, preventing her from crying our. The last remnant of her old pony form to go were her eyes, which continued to scowl up at Discord as he smugly watched her transform. Right up until her face melted into the rest of the diaper, leaving nothing but a typical diaper shape behind.

As the magics deep inside Dash began to settle she eyed Fluttershy who was waddling her way. The yellow pegasus didn’t seem all that invested in what was happening to her friend. Which was understandable, she had already seen it happen before to her other friends. Instead the mentally regressed mare aimed to snuggle up with her daddy, whom she loved very much. She reached for Discord’s leg to hug, but was stopped with a jolt as a pressing pressure gripped her insides. She groaned for a moment, bending over only slightly out of instinct as her trained bowels effortlessly filled up her diaper with yet another heavy, stinky load.

Discord’s nose twitched and he smirked knowingly at the mare who hugged his leg and sucked on her hoof. “And looks like you made it just in time! Somepony is in DIRE need of a change!”

Dash was powerless, unable to move, and barely able to think straight as the magic energies overwhelmed her mind. In the final moments of the transformation her vision began to fade, dimming into darkness as the rest of her senses dulled. Her hearing faded shortly after. Her sense of taste and smell all but vanished save for the lingering scent of baby powder.

A long wait in darkness passed before her vision finally faded back into focus as so did her hearing. She now felt Fluttershy’s body heat all around her and inside her. A strange sensation for the newly transformed pony diaper.

“There we go! Nice and dry!” Discord exclaimed, waving to the front colored panel of the Dash diaper, knowing all too well that Dash could see him. “Don’t we look cute!”

Discord tickled Fluttershy’s tummy, evoking happy giggles from the regressed pony as she squirmed under the draconequus’s hold. Dash felt her body morph and mold alongside Fluttershy’s movements, painlessly compressing and crinkling every which way.

“I bet some little pony’s hungry!” Discord exclaimed, “what better way to see how absorbent our little friend is!” He gave the front of the Dash diaper a confirming pat, grinning wildly at the crinkling thing.

With the diaper change a complete success, Discord waved a hand to lift Fluttershy up in the air. She was floated all the way into the kitchen where a large high chair was already set up.

Made primarily of bulky white plastic parts, the highchair appeared to be brand new and free of any of the usual wears and tears. It’s design consisted of smoothed edges, clean sloped parts, and assembled in such a way that it was almost impossible to determine where one piece started and one part ended.

Fluttershy was slipped effortlessly into the plastic chair as a threaded crotch strap pressed vertically into the Dash diaper’s front face to keep her from slipping out. Discord quickly conjured up some foalish delicacies in the form of small glass jars of baby food and placed them on the high chair’s tray. A bright pink, flower printed bib was magically tied around Fluttershy’s neck, signalling the beginning of the meal.

One by one, Fluttershy was fed the glass jars of brightly colored slop. Despite the food’s bland and watered down flavors of mashed carrots, pulped banana, and pulverized broccoli, happily opened her mouth to each one. She made a habit of not quite closing her mouth in time, leading to several brightly colored food splotches staining her bib.

Sitting so close to Fluttershy’s belly, Dash could hear the pony’s digestive system churn away as the food filled her up. The gurgling sounds served as a chilling reminder of what was to come if she didn’t somehow find a way to fix all this. But that in itself seemed impossible. She was just a diaper after all. All her friends were diapers.

The jars of baby food was quickly followed by a bottle of warm milk which Fluttershy hungrily snatched out of Discord’s hands. Despite not being able to dress herself, talk, or even walk properly, Discord found that when Fluttershy was hungry enough, she’d happily hold her own bottle of milk to suck down as quickly as possible. He didn’t mind it however, he found the image cute.

With a belly filling up with sweet milk, it was only a matter of time before Fluttershy’s bladder filled up enough for her regressed mind to notice. And once it was noticed, her foalish mind knew only one thing to do about it. As she continued suckling on the large baby bottle, a spray of urine began to pour into the waiting diaper.

Dash was mortified as she felt a strange warmth splash against what was once her chest, only to be absorbed into the diaper’s padding. The warm sensation spread outwards to other parts of her diaper body making Dash shudder at the alien and wrong feeling. She could feel herself swelling up as the urine soaked into her padded body.

Fluttershy was relentless with her new diaper’s absorbency test. In no time at all, a bladder’s worth of urine had emptied into the Dash diaper, changing the once pristine pale blue diaper into a muggy yellow hued one. Still working on the bottle of milk, Fluttershy didn’t bat an eye at the swelling garment that gave her a calming warmth around her waist.

“That feel good, Rainbow Dash?” Discord had watched the whole thing, smugly enjoying the sight of the Rainbow Dash diaper swelling up and becoming yellow. “You should be happy. Giving little Shyshy a place to do her business is such a relief for her. Just imagine how painful it’d be if she held it in for too long!” He teased the diaper, knowing full well that Dash could hear and see everything, but couldn’t respond in the slightest. “I bet you’re enjoying yourself. I mean how often can somepony just lounge about while also providing a little foal a comfy seat.” At the end of all that, he just shrugged before returning to feeding Fluttershy. “I guess it doesn’t matter if you are enjoying yourself. You’ll learn.”

After a few more minutes Fluttershy finished off the whole bottle of milk. She let out a breathy sigh as she suddenly remembered how much she had neglected breathing during her hungry feeding. The baby bottle was dropped, left to roll around wherever it might as Fluttershy just laid back in her seat. Moments later she reached up for Discord, squirming a tiny bit as she babbled some gibberish to get his attention.

Discord chuckled and knew just what she wanted. “Alright, diaper pants, up you go!” He lifted the diapered mare into his arms, balancing her head on his shoulder as he gave her back a couple pats.

Burping, like being able to feed herself, was one of the few adult skills Fluttershy still maintained throughout her regressed state, but she outright refused to do it without the help of her daddy Discord. When the need arose she would reach for Discord and make a little fuss about it. And Discord would always be there to help her.

A couple pats on the back was all that was needed for Fluttershy to let out a number of cute burps. “Aww, there we go! Happy tummy!” Discord cooed at the pegasus, giving her back a couple congratulatory pats. He even made sure to give the diaper a couple pats on the rear to make sure Dash wasn’t missing out on the fun. Once her burping needs were sated, Fluttershy became lax in the draconequus’s arms.

Discord held Fluttershy up in his arms, playfully nuzzling her nose. “Well now that we’ve had a nice yummy meal, I think a nice walk around town is just what we need!” Fluttershy just giggled, simply picking up on Discord’s cheerful energy. Her legs even wiggled in the air because she was so happy.

With a wave of his glowing hand, Discord conjured up a large, pink stroller, the perfect size for Fluttershy. It was a plastic framed vessel with a soft cushioned seat and a meshed basket underneath. Tiny wheels rolled freely on the wooden floor, promising just as gentle of a ride on the cobblestone sidewalks outside.

Fluttershy was teleported into the stroller seat as enchanted straps wrapped over her shoulders and clipped into a plastic lock centered on her front. Discord teleported behind the stroller conjuring up a soft pink diaper bag in the process.

“Now lets see what we can find on our little trip to town,” Discord commented, tossing the diaper bag into the bottom basket of the stroller. “I bet we can find plenty of ‘volunteers’!”

And with that, the three were off. Discord cheerfully pushed Fluttershy down the cobblestone path leading into town already dreaming up a list of fun things they could do when they get there. Rainbow Dash, still recovering from when Fluttershy peed in her, floated along for the ride in a bit of a daze. Despite all that she saw, she had the creeping suspicion that it was just the beginning.

Author's Note

And here it is, the first story in my list so far that I would count as "fetish". Sure technically any story that I've posted involving diapers has been considered "fetish", but I feel this is the point where things get rather kinky and might sour people off of reading. Diaper transformation, mental regression, and messy diapers aren't for everyone, but when this idea on my writing desk started to turn into a story I rolled with it and got this as an ending result.

If you made it this far I can only assume you either have a high tolerance for weirdness or are into the stuff. Thank you for getting this far. I have about two more chapters planned for this story so look forward to that if you're enjoying it.