Baby Makes Two

by FlatPancake

Rating: mature
Tags: Slice of Life, My Little Pony: Friendship is Magic, Fetish, Rainbow Dash, Fluttershy
Length: 7643

Fluttershy planned on spending an evening unwinding by indulging in some infantile fantasies. Unfortunately, Rainbow Dash has a habbit of bursting in unannounced.

Fluttershy has a side of herself that she has kept locked away, hidden from her closest friends and, in a way, herself. Only recently has she developed enough bravery to take the plunge and live out her taboo, infantile fantasies. One night, she decides to indulge from the safety of her home, away from prying eyes.

Unfortunately, Rainbow Dash has a tendency to burst in unannounced...

Contains ABDL themes, diapers, and diaper usage.

Published 2021-07-27 08:30:01 UTC
Last updated 2021-07-27 08:30:01 UTC

Intruder Alert

Fluttershy had no plans tonight.

She had already finished her chores around the cottage. All her animals had been attended to, Angel had been given a bowl of lettuce and carrot slices, and overall, everything that had to be taken care of had already been taken care of. As a result, Fluttershy had an evening to herself, which was a common but always welcome occurrence.

She was already dressed for the occasion.

Fluttershy gently glided down the stairs from her bedroom to her living room, a fuzzy teddy bear firmly clutched to her chest. A chorus of crinkles echoed throughout the walls of the cottage, emanating from the large white diaper she had taped around her waist. A light blue pacifier, the same color as her eyes, covered her lips. She gave it a suckle as her hooves touched the floor, and she pranced over to her couch.

Fluttershy had spent a few nights like this recently. She had always been curious, idly fantasizing about what it would be like to be young again; to especially be a baby again. But she never pursued it out of fear of being caught. It was too taboo; what would ponies think of her? What would her friends think of her? Or her family? It was a side of her she had kept locked up for years, too afraid to let it out.

Only recently, within the last month, had she finally worked up the nerve to go for it and live out her dream. She had put in a mail order for some adult diapers and an adult pacifier, which promised discreet shipping and had delivered on that promise. She wanted more, but just getting that much was hard for her, and more only meant she would have more things to hide when her friends were over. She figured diapers and a binky would be more than enough to make her feel like the baby she wanted to be.

And it was, though even then she was still nervous to let herself “baby out” as it were. She’d only gone through a handful of diapers in her pack, afraid to let them run out too quickly. She opted to save them for special occasions. They were very comfortable, and the crinkly sound the made when she walked did wonders to sell that distinctly infantile feeling to her. The taboo of it, however, made it difficult for her to get into the headspace she wanted, as if fearing that somepony would walk in on her at any moment. It felt wrong, but she still wanted it…

She shook her head to rid herself of those thoughts. She wanted to feel little tonight, to not have to worry about anything. She plopped down onto the floor of her living room, just in front of the couch, and squeezed her teddy bear to her chest. She gave her pacifier a suckle, and let out a sigh. It’s okay to be little tonight, she assured herself. Nopony is going to find out.

That was the precise moment when Rainbow Dash let herself in the front door. “Hey, Fluttershy! You left the front door unlocked again. Are you… free… to… uh…”

Fluttershy froze, pupils shrinking to pinpricks as the voice reached her ears. In an instant, she swiveled around from her spot on the floor, instinctively holding the teddy bear in her lap in a vain attempt to cover up her diaper. Rainbow Dash stood in the open doorway, seemingly frozen in place and staring in shock at her. The blue pegasus’s mouth flapped noiselessly, as if trying to form words but unable to get them out.

“W-Wainbow Da’!” The butter pegasus cried out. With horror, she realized her pacifier was still in her mouth. In an instant she reached up, plucked it from her lips, and fruitlessly hid it behind her back, trying her hardest to suppress a wince. “W-what are you doing h-here?”

Rainbow Dash continued to stare, slack-jawed.

“I-I can explain!” Fluttershy pleaded. “It’s not… I mean, it is, but… I mean…”

“Fluttershy, you’re a… you…” Rainbow Dash trailed off, raising a hoof towards her friend with eyes continuously growing to saucers.

“I… I’m not… I’m sorry, I….” Fluttershy clenched her eyes shut and trembled, awaiting the words from her friend that would seal her fate. Laughter, maybe disgust, something.

“Ohmygoshohmygoshohmygosh!” Rainbow blurted out at last. Confused, Fluttershy opened up an eye to see Rainbow Dash looking positively ecstatic. She had hopped into the air, clutching her hooves to her chest. A bright and toothy smile was beaming on her face, and in an instant the mare was upon Fluttershy, engulfing her in a strangling hug. Fluttershy fell limp in her grasp, too stunned to reciprocate. Rainbow didn’t notice. Her diaper crinkled loudly from the contact, and she felt a distinct longing for the teddy bear that she had accidently lost hold of in the sudden hug.

“R-Rainbow?” She found herself saying. “W-what….”

“This is so cool!” the colorful mare cheered. “I never thought that you… or any of my friends… that they would…. Eeeee!” she squealed, buzzing her wings like a hummingbird. She let go, and suddenly Fluttershy felt her diaper exposed for her friend to see again. She quickly shuffled over to her fallen teddy, cuddling him close again and staring at the blue pegasus in a wary mix of fear and confusion. She shuffled, again hearing the crinkles that should have been damning her to mocking yet for some reason… weren’t.

“Um, R-rainbow Dash?”

“Fluttershy! Are you doing anything tonight?”

“Um, well, no, but-“

“I’ll be right back! Don’t go anywhere!” The mare zipped out of the house, leaving a rainbow trail behind her. Before Fluttershy could even register her departure, Rainbow zipped back in. “And don’t change either! I promise you’ll like this!” Before Fluttershy could question her, she was gone again.

Unsure of how to respond to what had just happened, Fluttershy simply whimpered. She retrieved her pacifier and reinserted it into her mouth, giving it a few calming suckles. She held her teddy bear ever closer, feeling her emotions wage war inside her. Rainbow didn’t laugh, she thought, trying to console herself. In fact, she looked… excited?

Her instincts told her that was a bad sign. Rainbow Dash would certainly tell somepony. That was exactly what she was doing now, no doubt about it. Soon all of her friends would know Fluttershy was a freak who liked to put on diapers and act like a baby. There was no way she would be able to show her face again. She felt her eyes start to glisten. What was she thinking? Why would she think this was something acceptable? She buried her face into her stuffy, holding it in a vice grip and suckled her pacifier ever more intently.

She stayed there for a few more minutes, feeling herself spiral deeper and deeper into despair. Worst case scenarios filled her head. She thought she should change out of the diaper and put away her toys, but what was the point. Rainbow Dash had already seen it, and soon everypony else would know about it for certain. Everypony would know just how much of a freak she…

“I’m back!” Rainbow Dash announced, cheerfully flittering back into the abode. “This is going to be so awesome! You’ll love…. This?” Rainbow trailed off. Fluttershy could feel her eyes on her, but couldn’t find it in herself to peal her face out of the fluffy head of her teddy. “Hey, Fluttershy, you good?”

Fluttershy simply whimpered in reply.

A moment went by in silence, Fluttershy’s cries being the only sound. The butter pegasus felt a weight touch down next to her, and suddenly a feathery wing was draped over her.

“Hey, Shy, I’m not going to tell anypony about this, you know.”

That was enough for Fluttershy to break away from her stuffy and look over at her friend. “B-buh… buh I…”

“Hey, no buts! I wouldn’t do that to you. In fact, I got something to show you. I promise you you’ll like it.” With a final squeeze of her wing, the mare took off down her hallway. Only then did Fluttershy realize that Rainbow Dash had a blue and yellow duffle bag with her, likely her Wonderbolts bag. She carried it off and down the hall, and the pegasus could hear the sound of her bathroom door open and close.

Fluttershy waited at her spot on the floor, still holding her teddy bear tight. The fear had abated somewhat, though it wasn’t all gone. Instead it was replaced by a sort of morbid curiosity. She didn’t have much time to dwell on that though before the bathroom door opened again, and Rainbow Dash emerged. She rounded the entryway and hovered before Fluttershy, holding her hooves out to the sides in a showpony manner that belied the blushing, nervous look on her face.

“Tada!”

Fluttershy’s breath hitched as she took in the sight of her friend. The blue pegasus was dressed in navy blue and yellow outfit that matched her duffle bag. It had the same pattern and logos as a Wonderbolt flight suit, but that was where the similarities ended. It resembled more of a T-shirt, though with a much larger collar that seemed to stretch to her shoulders. The bottom stretched down the whole length of her torso and came together at the crotch, a series of three buttons holding the flaps together and keeping her hind legs exposed.

Rainbow Dash was wearing a onesie.

But it was more than that. Fluttershy’s eyes caught on to the white plastic that was sticking out the legs of her onesie, and the slight bulge that surrounded Rainbow’s waste. She was wearing a diaper. Finally, Fluttershy noticed the magenta pacifier that was sitting in her friend’s mouth, and the blue strap clipping it securely to her onesie’s collar.

Fluttershy’s pacifier fell from her mouth as her jaw went slack.

“R-Rainbow Dash… you…. You’re….”

Rainbow Dash’s smile faltered a bit and she blushed heavier. Her hooves clopped down on the floor as she landed and sat on her haunches, her diaper making an audible crinkle as she did so. She sheepishly rubbed a hoof on the back of her head, and let her pacifier dangle from her lanyard.

“Y-yeah, I’m… you know… also a, uh…” she gestured to herself.

“An adult foal?”

“Yeah, that.” She shuffled, clearly embarrassed. “I’ve just been kinda, you know, keeping it to myself. Never planned on letting anypony ever figure this out, but…” She smiled, holding out her hooves to Fluttershy as if presenting her. “But clearly I don’t have to worry about that with you… right?”

Fluttershy continued to stare in amazement for a moment. Her jaw closed, and a bright smile appeared instead. In a moment, Fluttershy closed the distance on Rainbow Dash, wrapping her in her hooves. She squealed in excitement. Rainbow Dash returned it with a sigh. After a moment, the blue pegasus broke away.

“So, if you don’t have anything going on tonight, do you wanna have a… you know… a play date?”

“A… play date?” The idea was so infantile, so childish. She hadn’t had a playdate since she was a little filly. The idea of playing baby with one of her best friends was a dream come true. “I wouldn’t want anything else!” Fluttershy returned, radiating joy. She wilted slightly as she looked over to her meager pile of toys on her rug. “I don’t have much though.”

“That’s fine! I brought some extra diapers and stuff. I’ve even got an extra onesie that I think might fit you, if you’d like.”

Fluttershy felt a tingle in her stomach at that. She didn’t have any baby clothes besides her diapers. It had been on her wish list, but she never knew the right way to go about acquiring them, nor did she have the nerve to find out. “Can I?” she eagerly asked.

“Yeah, totally!” Rainbow Dash quickly wandered over to her bag, a distinct waddle gracing her gait. Fluttershy couldn’t help but giggle at the sight. The blue pegasus soon pulled out a white onesie, this one with paw prints on it in various pastel colors. Fluttershy’s eyes twinkled as she beheld it, and she let out a squeal of delight as she hungrily reached for it.

Only, Rainbow Dash ended up holding it away from her with a sly smile. “Woah there, Shy! Babies can’t dress themselves, right?”

Fluttershy cocked her eyebrow for a moment until it clicked with her. “O-oh, right!” With a cute giggle, she plopped down in front of her friend on her rump and held her hooves up to the ceiling. Rainbow Dash laughed in turn, then draped the onesie over the butter-yellow pegasus head and pulled her hooves through the sleeves. She then gestured for her friend to stand up. Fluttershy obliged, and soon found Rainbow Dash circling to her rear. She blushed as she felt her friend buttoning up the snaps around her plush diaper.

“Aaand there ya go!” Rainbow eagerly announced as she finished with the last snap. With a smile brighter than the sun, Fluttershy quickly waddled over to a nearby mirror to take a look at herself. The onesie fit almost perfectly, perhaps being only slightly on the snug side. Nevertheless, she could feel it hugging her diaper to her rear tightly, and as she looked into the mirror her jaw dropped. The way the white garment bulged around her waist, and the way her onesie snapped in the rear leaving her legs bare, was positively infantile. Just as she had seen on Rainbow Dash, her diaper peaked out ever so slightly from her legs, adding magnitudes to the foalish look. She felt herself mouth a quiet “wow” as she stared at herself.

“Hey, Shy, I think you’re missing something.” She turned at Rainbow Dash’s voice, only to be greeted by the mare placing her pacifier into her agape lips. Fluttershy gave it a suckle in surprise, then another, then noticed the other thing Rainbow had in her hooves. With a smile, Rainbow held out her teddy bear, and Fluttershy accepted it. When she next looked into the mirror, all semblance of adulthood had fled like a bat in the light. Standing in the mirror was an oversized baby, clad in a onesie, sucking on a pacifier, and clutching her teddy bear. Fluttershy took it in for a moment, then clenched her eyes shut and let out a delighted squeal. She danced on her hooves, her wings sprouted outwards in excitement.

Fluttershy was a baby again, just as she had dreamed of.

“I guess that means you like it, then. You look adora- woah!” In an instant Fluttershy was on Rainbow Dash, embracing her in a bone crushing hug. “Gah! Fluttershy!”

“Ish’ perfec’!” Fluttershy replied through her pacifier, continuing to hold tight. “Than’ you sho mush!” Rainbow Dash hesitantly patted her friend’s back, then pushed against her should in an attempt to pry her off a little.

“No problem, Shy. You, uh… you make a cute baby.”

“You ‘oo!” To Rainbow’s relief, Fluttershy then pulled away, but no before picking up Rainbow’s pacifier and placing it in the mare’s mouth with a cute giggle. She then picked her plush teddy bear back up, then eagerly head it out in front of her towards Rainbow. “Weh’s Pway!”

And so, with an eager nod from Rainbow Dash, the oversized foals played.

Bottled Up

They started with stuffed animals, with Fluttershy eagerly showing off her small collection and Rainbow Dash procuring her plushie Spitfire doll out from her duffle bag. Together they played childish games of pretend, which soon expanded to include some of the wooden ABC blocks that Rainbow had thought to bring along with her. Time passed by quickly for the would-be babies as they laughed and played together, the movements of the clock being nearly imperceptible through their collective headspaces.

“Hey, Shy,” Rainbow started after a rousing game of block tower building. “You ‘irshty? I go’ shum ‘ottlesh.”

Fluttershy cocked her head, then sheepishly took out her pacifier. “What was that, Rainbow?” With a blush, Rainbow let her pacifier drop and dangle by her clip.

“I said, are you thirsty? I brought a couple bottles.” Fluttershy’s eyes twinkled, and she nodded enthusiastically. “Great!” Rainbow Dash shuffled to her duffle bag and began rifling through it, sticking her padded rear out as she did so. “Let’s see… diapers… baby powder… wipes…” Fluttershy’s heart skipped a beat at the mention of wipes. Would Rainbow Dash really…? “Aaaand bottles!” She pulled out of the bag with a plastic baby bottle clutched in each hoof as she hovered in the air.

“Y-you really thought of everything, didn’t you, Rainbow Dash?”

Rainbow Dash blushed, rubbing the back of her neck as she looked away. “We’ll… I sort of have lot of stuff at home.”

“Really? But, where do you keep it all? I’ve never seen anything for a foal the times I was over.”

“I have a room. That I keep locked.”

“Oh.” Fluttershy cocked her head. “Like a nursery?”

“Eh, sort of. I never bought any furniture or anything like that. Just, you know, toys and clothes and…” She trailed off, rocking her head side to side in hesitation. “…diapers. The basics, I guess.”

“Oh, that’s wonderful!” Fluttershy’s eyes nearly sparkled at the thought. “I’d love to see it next time I’m over.”

“Yeah, definitely!” She held up the bottles again. “So, uh…. What do you got to drink?”

Fluttershy giggled before walking up and taking the bottles from her friend. “Milk seems fitting. I’ll be right back!”

With a skip in her step, Fluttershy pranced over to her kitchen, opened her fridge and pulled out a jug of milk. She caught the eye of Angel, who stood on the countertop and staired at her inquisitively.

“Oh, isn’t this just wonderful, Angel! I never thought I would be able to share this part of me with anypony, let alone one of my friends.” She removed the cap from the two bottles and carefully filled each one to the brim with milk. The bunny quietly squeaked in response. “No, Angel, I don’t think she would tell anypony. Rainbow Dash is nicer than that, and I doubt she want’s anypony else to know about this either.” She screwed the rubber nipples back onto each bottle, then cheerfully scooped them up into her hoof. She made her way back to her living room.

She walked in to see Rainbow Dash holding her Spitfire plushie up on two legs, using the forelegs to knock down a block tower she had set up. “Gar! Everypony run from Spitzilla! Oh no! Ahhhhh!” she babbled, making her own sound effects as the blocks fell to the ground.

Fluttershy watched on, smiling broadly and letting herself giggle. At last she moved closer. “Okay, Dashie! I have a bottle ready for you now!”

“Yay!” Dash foalishly cheered before taking the bottle from her friend’s outstretched hoof. “Thanks Shy! You’re the best!”. The pegasus then promptly plopped onto her diapered rear, then brought her bottle to her lips with both hooves.

The sight was adorable. Clad in her onesie, with a pacifier dangling limply around her neck and the white plastic of her diaper sticking out the leg holes, Rainbow Dash sucked on her bottle with abandon. Fluttershy was about to do the same with her own, but then a thought struck her. She hesitated for a moment, unsure if it was okay, but after taking a breath she decided to go for it.

Rainbow Dash eyed her as Fluttershy crept forward, then behind. She stopped her suckling, feeling confused. “Uh, Shy? Aren’t you going to drink your…”

Fluttershy plopped down behind Rainbow Dash facing the same direction and wrapped a foreleg around her friend’s belly. Rainbow Dash let out a small yelp as she felt herself be pulled back until she was reclining into Fluttershy’s chest, the butter yellow mare’s rear legs held out to other side. Her cheeks lit up red.

“W-what are you…”

“I’m going to feed you your bottle!” She pulled the bottle out of Rainbow’s grasp and held it up to the blue mare’s lips for her. “That is if, um, you want to.” The bottle drooped and Fluttershy’s eyes drifted away. “I-I’m sorry, w-we don’t have to, we can-“

Rainbow Dash pulled Fluttershy’s hoof back up, directing the nipple of the bottle into her mouth. Once it was secure between her lips, she let go, and contently leaned her head into her friend’s chest. She began suckling immediately, and with a smile, Fluttershy nuzzled her friend. The feeding session went on for a few minutes, with not a word spoken between the two. Rainbow Dash did however let out a couple sighs of content, falling absolutely limp during the process. Fluttershy nuzzled her from time to time as the two got lost in the moment.

It was only broken when Fluttershy noticed a twitch in her friend’s leg. The mare stiffened, then just as quickly relaxed and continued her suckling. Fluttershy raised an eyebrow, then her cheeks brightened as she noticed the gentle hissing coming from Rainbow Dash’s diaper.

That answers that question, she thought. She became dimly aware of a similar mounting pressure in her gut, but it was still minimal. Besides, even with Rainbow Dash having done it, the thought of wetting herself in front of her friend still made her anxious and more than a little shameful. The continued hissing did make her curious though, and she made an attempt to relax as well. As expected, she couldn’t.

The hissing stopped a few seconds later, and the bottle ran empty soon after that. Rainbow Dash continued to suckle on the bottle even after it ran dry, only opening her eyes again when Fluttershy pulled away. She looked up at her with a smile.

“That was… wow. Thanks, Fluttershy!”

“Oh, it was, um, nothing really, I just, uh…”

“Want me to do you?”

“W-what?”

She wriggled out of Fluttershy’s hold and picked up the full bottle that Fluttershy had yet to touch. “I said do you want me to feed you too? It’s only fair.”

“Oh, um, sure, but… wouldn’t you like to, um… change first?”

“Oh, uh….” The Wonderbolt squeezed her rear legs together, causing a light squishing sound to eminate from her diaper. She gave herself a poke along the front of her waist as well. “Naw, I think I’m good for a while.”

“Are you sure?”

“Yeah, I’m sure. These Cloudies can hold a ton! I usually like to let them get way more full than this. I don’t think I’ll need a change for a while.” Her smile then dropped, as if realizing something. “Oh, ponyfeathers, are you not okay with me using them? Sorry, I should’ve asked first! I just assumed…”

“N-no, no, it’s alright!” Fluttershy stammered, rubbing the back of her head with a hoof, not making eye contact. Her blush deepened. “I just, well, I don’t have experience with… I mean, I haven’t…”

“Wait, you haven’t used your diaper before?” Rainbow Dash cocked her head, as if the concept of her fully grown adult friend not wetting herself was a weird concept.

“Well, um, no, not really…” Her hoof shifted from her head to her other foreleg. She could hear her diaper crinkle as she shifted uneasily. “I just never… I mean, I could never get myself to… I mean…”

“Hey, Fluttershy, it’s okay, I’m just surprised.” Rainbow Dash moved closer. She took hold of Fluttershy’s pacifier and placed it back into the yellow pegasus’ mouth. Fluttershy meeped, but otherwise took it without a fuss. The gentle suckling helped calm her down. “I figured if you were wearing diapers, you probably were into everything about ‘em.”

“’ish no’ dat.” Despite the pacifier making it hard to speak, Fluttershy didn’t feel any rush to remove it. “I ‘ust ne’ah try.”

“Soooo… you want to, but can’t get yourself to?” Fluttershy nodded. Rainbow Dash beamed. “Well, let’s change that then!” She scooted back slightly, holding a hoof over her onesie-clad heart. “I, Rainbow Diaper Dash, will teach you all about the art of peeing in your diapers!”

It was an absurd statement, one that she would never have in a million years expected to come out of a proud mare like Rainbow Dash’s mouth. Especially out of Rainbow Dash’s mouth. It felt so off-brand, and yet somehow still in character for the brash and cocky pegasus. Fluttershy couldn’t help but giggle, which quickly turned into full-on laughter as her pacifier fell out of her mouth. Rainbow Dash blushed, then joined in too.

“Oh boy,” she started, wiping a tear from her eye. She adopted a stern glare and jabbed a hoof in Fluttershy’s direction. “If you tell anypony I said that, I’ll deny it!”

“I wouldn’t dream of telling anypony that you enjoy wetting your Cloudies to the brim, Rainbow Dash,” Fluttershy responded between giggles.

“And don’t you forget it! Now, come on! You still have a bottle to drink. Just relax and think about flowing water or something.” She positioned herself similar to how Fluttershy had done earlier, holding the bottle up in invitation. With a smile, Fluttershy nestled between Rainbow Dash’s legs. She could faintly feel a squish from Rainbow’s swollen diaper impacting her own, but decided not to let it bother her. Instead she simply let her head rest on Rainbow’s chest. The bottle was brought to her lips, and Fluttershy started to suckle.

It was slow going, at first. The teat of the bottle delivered milk in a tiny stream, but as she worked it more and got into a rhythm, the milk flowed faster. Or perhaps she had simply gotten more comfortable with it. She wasn’t sure which, but between the rhythmic suckling of the bottle and the steady thump of her friend’s heartbeat, Fluttershy was feeling thoroughly blissful. She let herself go completely limp in Rainbow’s hooves.

“Let it go,” Rainbow Dash softly whispered in her ear. “That’s what your diaper is for. Just relax, and let it out.”

She didn’t reply, too lost in the bottle. But she did still try. Almost on cue, her bladder twitched. She instinctively held it, but then decided to focus on the bottle. She focused on the milk. She focused on Rainbow’s heartbeat.

Suckle.

Thump, Thump.

Suckle.

Thump, Thump.

Hissss…

She almost didn’t realize when it started happening, but it was hard to ignore. She felt her diaper grow warmer, and tried to continue focusing on the bottle feeding as the trickle of urine turned into a stream. Her heart started racing, but she kept her eyes closed and continued to suckle. It flowed faster and faster, and instinct pestered her that she was going to leak, that she was going to make a mess of her floor, that she was going to ruin her adorable onesie and maybe even Rainbow’s. She pushed that instinct away, holding it at bay as it thrashed and screamed inside her, telling her that this was wrong.

And yet, it felt so right.

The stream became a trickle again, and eventually she was finished. All that was left was a very warm and now very swollen diaper, which spread her legs even further apart. The sensation was downright electrifying, and she let out a sigh around the nipple of the bottle as she squished her thighs together. Satisfied, she let herself go limp once again and finished off her bottle.

Once it was empty, Rainbow Dash pulled it away, but didn’t attempt to remove Fluttershy from her position. “So,” she began eagerly. “How was it?”

“It was wonderful.” Fluttershy sighed again, eyes still closed. “I never thought I’d ever feel this young again.”

“Heh, yep! Nothing makes you feel more like a little baby than going potty in your pants.” She softly pressed a hoof into Fluttershy’s diaper, causing Fluttershy to meep in surprise. “Wow, you really went all out for your first time.”

“I-I really had to go…” She blushed, then followed suit with checking her own diaper. It squished and squelched as she prodded the front and bottom with a hoof. It had swelled up considerably, and yet she detected no wetness anywhere on her onesie. Her diaper had done it’s duty admirably, soaking up everything she threw at it. “Should I change?”

“Do you want to?”

“I…” Fluttershy squeezed her legs again, and felt a jolt of electricity race up her spine at the sensation. She had wanted this. She wanted to keep enjoying it. “…No.”

“Then don’t!” Rainbow cheered as she let her friend go and stood up. “We’re just babies! Big babies who don’t care if their diapees are wet or messy! Playtime is more important!”

“M-messy? Do you – oh!”

Rainbow Dash flapped her wings as she pulled Fluttershy to her hooves. “C’mon, ‘Shy, it’s time for us soggy babies to play! I even brought a coloring book!”

Fluttershy shook herself out of her momentary surprise and nodded with a smile. “That sounds fun, Rainbow Dash!” She placed her pacifier into her mouth. “Le’s go!”

The Threshold

The two onesie-clad pegasi attacked the coloring book with abandon.

It was a Wonderbolts themed coloring book, though an older one if she had to take a guess as her friend was not yet featured in it. Many pages had already been filled, and what had stood out to Fluttershy was the quality of each page. Some pages truly looked like a foal had gone at it with one or two colors of crayon, paying no heed to the lines or color accuracy. Other pages, though, were colored in perfectly between the lines, colored to match the real-life ponies it depicted perfectly. Those ones weren’t bad even, as if Rainbow Dash was really trying.

She asked about it at the start while they were flipping to a fresh page, and Rainbow Dash blushed. “I like coloring,” she said, rubbing her foreleg. “But sometimes scribbling just feels, I dunno… right, I guess.”

Fluttershy hummed at the thought, then grabbed hold of a purple crayon and began coloring Fleetfoot’s mane. She started by keeping between the lines, but then stopped and looked at Rainbow’s progress. She was currently coloring her fellow Wonderbolt’s tail yellow, in stark contrast to the purple mane. She was scribbling excitedly, and so Fluttershy decided to follow suit. The lines were forgotten, and by the end they were barely noticeable in the miasma of waxy pastels.

“I do’n’ ‘ink ‘Fwee’foo’ wou’ appreshia’ dis” Fluttershy babbled around her pacifier with a giggle as they put on the finishing touches, namely a mustache that Rainbow was drawing on. Rainbow Dash giggled in response.

“I sheen worsh.”

The two continued to color page after page, suckling their pacifiers all the while. Occasionally, Fluttershy would let herself bounce on her rear, for no other reason than to feel her diaper squish under her again. Each time sent a wave of excitement through her, making the pegasus feel pride in her babyishness. Eventually though, the warmth of Fluttershy’s diaper faded, as did her enjoyment of the soggy garment. It began to feel clammy against her skin, and while the squish was still there it had lost some of its luster. Only now did she consider changing.

Only, she didn’t feel like she was done. She certainly felt as if she had more to give the swollen diaper. Something different. She was trying to be a baby after all, right? That’s certainly what babies do in their diapers, not just wettings. But for some reason, the thought still made her uncomfortable, like it was a step too far. A line that she shouldn’t cross.

But Rainbow Dash had alluded to that before, right? ‘Babies don’t care if they’re wet or messy’, she had said. What did that say about Rainbow Dash? It was hard to imagine the prideful pegasus doing that, but then again, so was everything else she had shown her tonight.

She pulled her pacifier out of her mouth. “Um, Rainbow Dash?”

“Hm?” her friend replied, still focused on her scribbling.

“How far do you like to go with, um…” She fidgeted with the crayon she was holding. “With your, uh, diapers.”

“Wa ‘oo you mea’?”

“Do you, um, do everything in them?”

Rainbow Dash spat out her pacifier. “You mean, do I poop in them?” Fluttershy blushed a bit at the blunt reply, and nodded. Only then did she notice Rainbow Dash was too. “Would… Would it be bad if I did?”

It was odd. This whole night, Rainbow Dash had somehow been exuding a sort of pride and confidence in her infantilism, which had come as a complete surprise and shock to Fluttershy. She would speak eagerly about her coloring books, her onesies, her bottles, and her diapers, going so far as to brag about her wet diapers. Amongst all that, it seemed weird that this would be the line for her.

But then again, wasn’t it the same for Fluttershy right now?

“N-no, not at all. I’m just curious.”

Rainbow Dash shifted uncomfortably, letting out an audible squelch from her diaper. “I do… sometimes.”

“Oh. Okay.”

The two sat in awkward silence for a moment, not looking each other in the eye. Rainbow was the first to break it. “Why do you ask?”

“I, um, sort of need to… do that.”

Rainbows ears perked up. “Oh? Well, okay! I’m cool with that if you are.”

“B-but that’s the thing. Do you…” Fluttershy twirled her hooves. “…like it?”

“Do I like it? Uh…” The blue pegasus picked up her crayon again and continued scribbling as she spoke, breaking eye contact again. “It depends. Usually, yeah.”

“Not always?”

“Nah. It’s almost always fun to do in the moment, but the cleanup usually sucks and so does the smell. Wetting is way easier.” She sighed. “It definitely makes you feel like a baby though.”

“Oh…” She rubbed her hoof awkwardly. “So… you don’t think I should?”

“Hay, no!” Rainbow replied instantly, perking up. “If you’ve never messed before it’s totally worth trying! Just, you know, you might or might not like it. It’s pretty gross.”

“Is that why me mentioning it is making you uncomfortable?”

“I’m not uncomfortable!” Rainbow stiffened as she replied, looking back up at Fluttershy. “I was just… worried that you would be, you know? I didn’t wanna gross you out. You seem pretty new to this, and I didn’t want to scare you off.” She sighed again. “I… never thought I’d get a playmate. I don’t want to lose that.”

Fluttershy lurched forward and pulled her friend into a tight hug, which caused Rainbow to yelp in surprise. “You don’t have to worry about that, Rainbow Dash. I never thought any of my friend’s would be like me either. I’m just so happy you are!” She squeezed tighter.

“Well… cool!” Rainbow Dash choked out, evidently struggling to breath. “You should probably let me go now so you can, uh, go!”

Fluttershy nodded and let go, blushing hard. “Oh, r-right.” She backed up from Rainbow and spread her legs slightly. “H-here I go!” Then, she closed her eyes, lifted her tail, and pushed.

Or rather, she tried to. Nothing happened for some time, and she nervously peaked an eye open to see Rainbow Dash staring at her expectedly. She flushed then, realizing her friend was watching her attempt to soil herself. “Um, R-Rainbow?”

“What’s up, Shy?”

“Can you, um, look away? W-while I do this?”

Rainbow Dash had the courtesy to blush at that moment, then stammered. “Oh, yeah, uh, right. I’ll just… color, some more.” Fluttershy watched as she shifted her position before the coloring book, putting her back to Fluttershy to give her some privacy. It would do.

Fluttershy decided to make another pass at it. Feeling like she needed something to comfort her, she placed her pacifier in her mouth and scooped up her teddy bear into her right foreleg. This time, she let her hind legs squat, giving her a more comfortable position for the act. She pushed again, and again, and again.

On the fourth time, she felt something move within her, pushing itself out slowly and steadily. Fluttershy’s heart raced, and she felt a tingle through her spine as she committed to her taboo and infantile act. She pushed again, and the weight finally settled into the rear of her diaper. Then she pushed again, then again. She continued until she was empty.

In the end, she could feel her diaper sag beneath her under the new load. She shuffled on her hooves, feeling the diaper jiggle between her thighs at the motion. It was an odd sensation. It wasn’t comfortable, though it wasn’t entirely miserable. Then the smell hit her. Her work with animals had made her accustomed to such scents, but she wasn’t used to it coming off of herself. It was a lot to take in.

But she had done it, she realized. She had fully used her diapers. Here she was, clad in a onesie, holding her teddy bear, suckling her pacifier, and wearing a wet and poopy diaper. There was no denying it now; she had crossed the threshold of adult babyhood. And despite her contrasting feelings of her diaper’s current state, she felt complete.

She practically squealed behind her pacifier and trotted in place in excitement. This made her mess jiggle around even more, drawing her back to the present. Taking another breath, she waddled back to her friend, attempting to not spread it around too much.

Rainbow Dash sniffed as she approached, and she looked up from her coloring with a smirk. “Smell’s like somepony made a poopy!”

Fluttershy blushed furiously, but couldn’t help but giggle at her friend’s cutesy tone. “I may’ a poopy!”

Rainbow Dash smiled and waived a hoof exaggeratedly in front of her nose. “No kidding. So, how was your first one?”

Fluttershy dropped her pacifier. “It was, um… it was fun. I think I want to change though.”

“Yeah, I get feel you. Sometimes it’s only fun for a few seconds. I know you have some of your own, but I’ve got some more Cloudies in my bag if you want to try those. And some wipes.”

That’s when Fluttershy got an idea; one that made her blush harder than she had all day. She bounced on her hooves nervously, looking at the bag Rainbow Dash had mentioned.

“You okay, Shy?”

“F-Fine,” she replied at a mouse’s volume. She hid behind her hair as if in instinct. “I-it’s nothing.”

“No way, something’s totally bothering you.” At that, Rainbow Dash got up and approached Fluttershy, looking at her sympathetically. “What is it?”

“I-I just, um… What if you, um….”

“Yeah?”

“What if you…. changed me?” Rainbow Dash’s eyes widened, and a wave of panic rushed through Fluttershy in an instant. “I-I’m sorry, that was too far, forget I said anything!”

“Ch-change…. Uh….” Rainbow Dash shuffled form hoof to hoof, clearly uncomfortable.

“I-I’m sorry!” Fluttershy’s heart raced, and she could feel a sweat start to build. She shouldn’t have mentioned that. She shouldn’t have even thought that. It was disgusting. It was too much to ask anyone. How would Rainbow Dash ever even look at her the same again?

Apparently, pretty easily, as she felt two blue hooves grab each side of her face and pull her towards their owner’s. “Hey, snap out of it, ‘Shy! I’m just surprised. You’re cool!”

“B-but I –“ she was cut off as her pacifier was shoved into her mouth. She immediately started suckling, desperate for comfort.

“I’m not mad! I just… never thought about changing someone else before. It’s a little weird.” Rainbow clammed up immediately. “Not weird! I mean, uh, different!” she sighed, looking down for a moment. When she brought her eyes back up to meet Fluttershy’s she said “Do you, you know, want me to?”

Fluttershy looked away, but nodded her head.

“A-alright. That’s cool. I mean, it can’t be grosser than changing myself, right?”

Fluttershy looked back in surprise. Her eyes practically sparkled. “Weally?”

“Uh, huh!” Rainbow nodded, looking as if she was more trying to convince herself. Nevertheless, she pulled on Fluttershy’s hoof, guiding her to the corner of the room with the bag of Rainbow’s supplies. “C’mon, lets get the baby out of that stinky diapee!”

Fluttershy’s heart raced as she followed her friend. She scooped up her teddy bear along the way, clutching it to her chest. At Rainbow’s request, she laid down on the floor on her back, making an effort not to squish her mess against her any more than she had. Rainbow Dash in turn sat down between the butter pegasus’s hind legs. She hugged her teddy bear tight, and suckled her pacifier anxiously.

Meanwhile, Rainbow Dash retrieved a new diaper from her pack. Unlike her plain white diaper she was currently wearing, this one had adorable cartoon clouds printed on the landing strip, each with a smiley face on them. Light blue clouds peppered the remaining plastic. It positively radiated foolishness, and Fluttershy’s eyes glimmered at the sight. Rainbow pulled out a bottle of baby powder along with a packet of wipes. She then unfolded the diaper, making sure to shake it around as she did so, fluffing it like a pillow. Fluttershy never considered doing that herself.

“Okay, then, let’s see how bad the damage is.” Rainbow Dash unfastened the buttons around Fluttershy’s crotch and pulled back the flap of the onesie, exposing the well-used diaper beneath. As expected, it had swollen considerably and the white shell had turned a subtle yellowish tint. A noticeable bulge stuck out near the bottom, providing evidence of Fluttershy’s latest infantile deed. Her blush deepened, feeling herself become more and more exposed before her best friend. “Heh, you really went all out, ‘Shy!”

Fluttershy squirmed a little at the tease and her heart beat faster. She tried to relax and let her head back, closing her eyes and thinking of just her pacifier. Meanwhile, Rainbow Dash slowly ripped the diaper’s tapes open one by one. Fluttershy hugged her teddy bear tighter as the soiled diaper was peeled away, putting herself in full view of her friend.

To Rainbow Dash’s credit, the pitiful whine the boisterous pegasus let out as she beheld the gross task ahead of her was brief. Despite that, she quickly got to work. At her instruction, Fluttershy lifted her rear up enough for Rainbow to remove the soiled diaper. Then, in a bit of a rush, she wiped Fluttershy clean. Fluttershy kept her eyes closed and head back. She was only mildly aware of the gagging noises her friend made as she performed her task. She then felt a prod on her backside, signaling her to lift her backside up again. She complied, and when she settled down again, she was resting on a fresh, fluffy diaper.

“Almost done,” Rainbow said more to herself than to Fluttershy. Fluttershy felt a sprinkling of baby powder land on her, and then heard the crinkle as Rainbow Dash brought the front of the diaper up and over her waist. Then one at a time, the blue pegasus pulled the tapes in, securing her into the fresh garment. “Aaand… done!” She announced as the last tape was applied. “A nice, clean diaper for the big baby! Now we just gotta snap this up…”

Fluttershy opened her eyes, smiling behind her pacifier as she felt Rainbow fasten the snaps on her onesie again. Once that was completed, she sat up and looked at her friend. Rainbow wore a smile, albeit one that was a little strained. “So, how’d I do?”

She let out a yelp as Fluttershy leapt forward, hugging Rainbow Dash tight. “Ih’ wah ama’ing!” she babbled. “T’ank ‘ou sho ‘ush!”

“Uh, no problem! What are friends for, heh heh.” She awkwardly patted Fluttershy on the back. “That may take some getting used to though.”

Fluttershy giggled. “I ‘an shansh ‘ou ‘nesht if ‘ou wan’”.

“Sorry, what?”

Fluttershy let her pacifier drop, catching on the lanyard. “I said I can change you next, if you want. That seems only fair.”

“Heh, naw, I think I can wait. But I’ll take you up on that in the morning. I’ll need to give you something to match!” Both oversized babies laughed at that, then settled into the hug again. They stayed like that for a moment until Rainbow Dash let out a mighty yawn.

“Tired?” Fluttershy asked.

“Kinda, yeah.”

“Well, it is getting late. It’s bedtime for us babies!” She giggled. “Come on, you can sleep with me tonight.”

Rainbow nodded, and Fluttershy took her friend’s hoof, leading her up the stairs into her bedroom. Rainbow followed dutifully, eyes half open. They reached her bed, and Fluttershy quickly directed her friend under the covers. Rainbow smiled as she was given her pacifier again. She was tucked in, then Fluttershy fluttered to the other side and slipped under the covers herself. As soon as she was nestled under the covers, she felt Rainbow cuddle into her, holding her tight. She relaxed, and turned to return the embrace.

“Thank you so much, Rainbow Dash,” she mumbled, feeling tired herself. “I had so much fun tonight.”

“Mhmm,” Rainbow Dash mumbled. “Gotta do dish… agai’… shometi’…”

“Uh, huh. But, um, you really should knock, next time.”

Rainbow Dash didn’t respond, her breathing falling into a steady rhythm. With a smile, Fluttershy put in her pacifier, cuddled further into her playmate, and let herself drift off into a blissful sleep.

She slept like a baby, and she wouldn’t have wanted it any other way.