Birthday Balloons

by AppleOfThineEye

Rating: mature
Tags: Fetish, Rainbow Dash, Random, Pinkie Pie, My Little Pony: Friendship is Magic, Romance, Porn
Length: 3247

Pinkie invites Dashie over for a pre-birthday surprise. Little does the pegasus know that there's some inflationary fun awaiting both of them. Fun they don't want to end.

It's the day before Dash's birthday, and Pinkie has invited her over to Sugarcube Corner for a surprise. When she arrives, the party pony leads her upstairs and -- with the help of magic cupcakes and some helium -- shows them both a blast of a time.

Includes: anal insertion, inflation (obviously), rubberization, squeaking, mental change, popping, identity loss

Co-written by superfun

Published 2022-05-09 22:50:01 UTC
Last updated 2022-05-09 22:50:01 UTC

A Blast at Sugarcube Corner

Pinkie Pie hummed a happy tune as she finished setting everything up in her room. She wanted everything to be just perfect when Dashie got there. It was a day before the pegasus's birthday, and the party pony really wanted to give her an early present to her best friend to celebrate. The equipment was heavy and hard to hook up just right, but the fun Pinkie considered the pair would have was motivation enough. It took not long after she'd finished to hear a knock on the front door. She bounced giddily down the stairs and towards the door, beaming ecstatically.

On the other side of the door was her rainbow-maned pegasus friend, floating in the air as usual. "Hey Pinkie. You said you had something to show me?" she asked as she landed inside, stomach rumbling a bit as she looked around the inside of the shop.

"Hi Dashie!" Pinkie greeted back, chipper as ever, trying not to giggle too hard about her friend's stomach rumbling. "Yeah, it's a surprise! Come on, follow me upstairs and I'll show you. Oh!" Almost having forgotten, the pink party pony reached out of sight and retrieved a cupcake with cyan frosting. "Here, this is for you too! You sound hungry, hehehe!"

"Heh, thanks," Dash said, chuckling a bit as she ate the cupcake before following Pinkie upstairs. "You're definitely pretty good at surprises, so I'm looking forward to what you have in mind."

As she bounced along, Pinkie giggled, knowing Rainbow couldn't possibly have any idea what lay in store in her room. "It's a very big surprise," she promised as she reached the top step, stopping and looking towards the pegasus. She smirked. "Close your eyes," she requested playfully.

"Alright. Must be a really good one, though," Dash said as she closed her eyes. "Should I hold my hooves out for this, or no?" she asked.

"Just one so I can lead you to the surprise!" the earth pony chirped, taking one of Dash's hooves enthusiastically before opening the door to her bedroom. Inside, there were helium tanks hooked up, disconnected from the balloon carts they were once a part of. There were two tanks just a couple yards apart, which Pinkie grinned at as she led Rainbow into the room. The ceiling was covered in balloons of all the colors of the rainbow, plus pink ones to boot.

"Can I open my eyes now?" the pegasus asked, smiling a little as she heard the door open and they walked inside, curiosity now as high as it could possibly get.

Closing the door behind them with a hind-hoof, Pinkie shook her head with a grin. "Uh-uh, not yet!" she chided, leading the pegasus between the two helium tanks. One blue, the other pink. She let go of Rainbow's hoof for a moment, readjusting Rainbow's position so that she was standing just a few inches in front of the blue tank, her posterior pointed at it. "Oooooone secooooond..." Pinkie insisted, quickly moving to make sure things were all lined up.

"...One," Dash said, chuckling a bit as she did, though not opening her eyes right away, not even questioning why Pinkie moved her.

Pinkie giggled, but it was a dubious little giggle. Even slightly sexual. Mouth salivating at the sight of Rainbow's plot, the party pony gave a wide grin before grabbing Dash's tail and giving it a firm upwards, exposing her anus. Wasting no time, she pulled backwards, sticking the nozzle of the tank right into her horse's ass. Her hoof quickly found the faucet of the tank. "OkayYouCanOpenYourEyesNow!"

She had already started opening her eyes upon feeling the nozzle in her rear. The sensation caused her to look behind her and finally see the helium tank. "Uh... Pinkie... what's up with this?" she asked before looking ahead and noticing the pink tank. "And what's up with that?!"

"Oh, that one's for ME!" Pinkie beamed, giggling as she turned the faucet, which made the nozzle of the blue tank start to hiss. She gave the pegasus's ass a spank while she had the chance, quickly kissing it as a cute little apology before backing away, back into Dash's view. "Happy early birthday!"

"Mind telling me what's going on?" Dash asked, moaning a bit at the spank before giving her ass a few shakes to try to dislodge the nozzle, to no avail.

"It's your surprise!" Pinkie said as though it were the most obvious thing in the world, booping Dash on the nose as she began to scoot herself back towards the pink tank. "Don't worry, that cupcake you had will help! I had one earlier too! It makes this a lot more fun, hehe..."

"I'm not sure I like this surprise," Dash said as she felt some of the air from the tank slowly start to enter her. "Please tell me what it actually is beyond that."

"Oh relax, silly-billy! Don't POP a gasket!" Pinkie giggled, grinning from ear to ear. "It's just a bit of magic and helium! Some people say we're airheads, so I thought it'd be fun to prove them right!"

"What?!" Dash gasped in shock, trying to reach behind her to remove the nozzle. "I thought you said this would be fun! I don't think this is fun!"

Pinkie put a hoof on Dash's head, trying to calm her down. "Dashie, it's okay! Just take a breath! It doesn't hurt -- it actually feels great! And besides, I'll be doing it too!"

Despite her still immense worry, Dash did slowly take a breath before looking Pinkie in the eyes. "Are... are you sure about this?"

"What could possibly go wrong?!" Pinkie exclaimed, giving Dash a reassuring smile. "You're my best friend Dashie! Just enjoy it!" Unable to help herself, Pinkie leaned her head forward at the same time she jutted her rear onto the other nozzle, kissing Dash.

Dash closed her eyes a bit as she returned the kiss, wrapping her forehooves around Pinkie's body, leaning into the kiss as much as she could.

Surprised by the return of affection, Pinkie giggled between their lips and let her tongue play with Dash's. One hoof slung over Dash's shoulder while the other turned the faucet on her own tank, now two hisses in the room.

Dash slowly pulled away from the kiss to take a breath, settling into place as she felt the air of the tank continue to spread through her body.

Pinkie, too, relaxed her puffy pink ponut against the nozzle, letting it do what it needed to do. Already she could feel the helium in her stomach, and she could see it in Dash's. She giggled. "Looks like SOMEONE got preggy!" she teased.

"Yeah, well same to you. And you look even more pregnant than I do," Dash said after giving their bellies a quick glance.

"Well now I guess we'll just have to deal with a bunch of little balloon babies," Pinkie winked. The pink pony mirrored Dash's movements, looking down at their tummies, from which their bellybuttons were sticking cutely. She rubbed her belly, feeling the air that it was swelling with. She pushed on it slightly, and some helium pushed out her muzzle, which tickled her throat and caused her to giggle.

Dash had a bit of a different idea in mind, sitting down as best she could and pressing one side of her rear against the floor, creating a squeaking noise.

Unsurprisingly, the nozzle followed her, and she ended up grinding against the tank that it was attached to. The squeaky sound made Pinkie giggle. "NOW who's the bubble butt?" she taunted, blowing a raspberry at the pegasus.

"Still you. I think you've had more sweets than i've had air," Dash taunted right back as she wiggled her ass against the tank, making more squeaks.

"I'm not the one whose butt squeaks and whistles!" Pinkie exclaimed with feigned indignity. She then laughed and began to squeezed her hind legs together, feeling as her thigh-flesh began to thin and rubberize. And, more importantly, squeak!

Dash felt a similar sensation, except her changes started at her already squeaking rear. "Oh man... this... this feels so weird..." she said, though a smile was still on her face.

Pinkie, too, was smiling. Beaming, even. She tried her best not to erupt in a giggle fit. "It... hehe... it tickles!" she managed, rubbing her squeakier-and-squeakier thighs together even faster, til they sounded just like a pair of balloons. Her plot began to expand too, and her midsection was off to a good start as well. Already she felt tens of pounds lighter!

"Yeah, it... it does," Dash said, starting to laugh a bit as well as her wings started to flap a bit as the rest of her body continued to turn into rubber. As this happened, the squeaking of her rears continued to get louder as she rose into the air, losing more and more weight the rest of her that converted into rubber.

Pinkie wasn't too far off. Anchored only by the tank, the pink pony began to feel the sense of zero gravity, quietly -- and almost stupidly -- going "Weee..!" as she began to float up, hind legs leaving the ground. Her tail was losing the definition of individual strands as it, too, rubberize. The parts of her that were further along began to shine like latex, like they were supposed to.

"I feel like I could break all kinds of speed records now," Dash said, flying as high into the air as she could, her tank likewise being the only thing keeping her from floating any higher. Her wings started to convert into latex, though she could continue to flap them for a bit even as this happened.

The feathers inflated, losing definition of anything more than bulbous, almost phallic appendages. Pinkie laughed upon seeing the pegasus being reduced to a balloon, happy that the same was happening to her. She began to "swim" upwards as far as her ponut would allow her to stretch, her tail now entirely latex. The tip squeaked against the tank almost adorably.

Dash did the same, flapping her wings until they no longer could, falling still as the body immediately around them also started to rubberize and turn into latex. "So... how long are we going to spend as balloons anyway?" she asked.

As Pinkie's torso progressed towards its desired goal of latex, the pink pony giggled. "Just until our butts come off the tanks!" she answered chirpily, enjoying herself by rubbing her inflated, rubberized tummy some more. It felt so perfectly empty.

"How long you think think that'll take?" Dash asked, not really caring about the answer but curious about it anyway as she pressed her rubber ass back against the tank to hear some more squeaking.

Pinkie listened almost lovingly to the sounds of her tail, tummy, and thighs making symphonies of squeaks. it took her a few moments to register the question. "Hehe... I dunno!" she declared uncaringly but unworriedly, looking down with a grin as her chest progressed towards being nothing but balloon.

Dash did feel a bit worried that not even Pinkie knew the answer, but that slight tinge of unease was vanished by another squeaky sensation as her latex spread up her back in both directions, her neck slowly turning into rubber.

Pinkie wasn't far behind. She could feel even her lungs start to dissipate in the helium, and her voice got marginally higher-pitched as she looked down at her front hooves, which were also starting to rubberize properly.

Dash's rear hooves started to rubberize as well to match her ass, though the rubber at her front continued to march up her neck, slowly reaching her head, starting with her mane.

Pinkie's rear hooves began to squeak, and she happily knew that soon she'd be done. What remained of her front hooves, she rubbed together to speed up the latex's spread, until they were as she thought they should have been: perfectly squeaky. She giggled as the rubber began creeping up her jawline and convert her own mane, just as it had her tail.

Dash rubbed her forehooves against her now rubberized belly, likewise speeding up her own transformation down them as her head continued to turn into rubber, her eyes and muzzle being the next parts of her face to change.

As she continued rubbing over herself happily, Pinkie couldn't stop laughing as her own muzzle started to change, curving into a grin she couldn't wipe away. Not that she would even if she could. Her mane finished changing, and next were her ears, which quickly filled with the sound of helium running through her body. Running through her head, even.

Dash's mouth likewise changed, though instead of a grin, hers was more her usual cocky smirk, though it was also permanently affixed to her face. With that out of the way, her chin and ears both started to rubberize as well, only taking a few seconds for both.

As she neared completion, Pinkie reached forward with her rubberized hooves and looked into Dash's eyes so that her best friend could watch as the last of her face -- her own eyes -- finished. Going, going... and just like that, rubber like all the rest.

Dash returned the gaze as her own changes finished, leaving her entirely rubber as well. And though she could no longer move her body, she could still feel through it.

Pinkie was just the same. No control, but a dull sensation all over her body. Her pink pony pussy had long since sealed up, not that she'd cared. Now all over she felt a undeniable pleasure, especially as she and Dash got bigger and their faces began to rub against one another, almost kissing.

If Dash could, she'd moan a bit as this happened, her own hole sealed up as well. As the air continued to fill her up, she worried that the hose would end up falling out of her and remove all of the pleasure.

Pinkie felt her own ponut stretch, and she too worried about herself being robbed of this. She wanted to feel like this, with her friend, for a loooong time. Their chests pressed against each other as they got bigger, their muzzles squishing into one another in a way that felt better than almost any time they'd ever touched themselves.

Despite knowing that the rubber kept her from moving, she did instinctively try to move her forehooves to hug Pinkie. This, of course, did nothing, though she couldn't really bring herself to care, the pleasure overriding any other sensations or thoughts.

Pinkie had been trying to hug Dash ever since she first lost control of her front hooves, even if it was futile. She wanted nothing more than to squeak against every inch of her friend. Luckily for both of them, more squeaking was exactly what they had in store as their bodies were pumped full of helium, their hooves squeaking almost lovingly together as they were pressed into an almost intimate embrace of latex.

The embrace also seemed to only increase the pleasure that the two of them were feeling, the air continuing to flow into them now making the two of them take up about half the room, with that amount only growing every second.

Chest and hooves and muzzles pressing against one another, it was hard to imagine they'd ever had pussies. This felt so much better. And yet, no release! They needed more! Pinkie wanted so desperately to grind against her tank and be filled with more helium to better please Dash and herself.

With the way the two continued to press against each other, it seemed like they were going to get their wish, as their bumping caused their bodies to shift in just the right way to allow more air to flow into the two of them.

Indeed, and so heavenly did it pump them silly. Bubble butts, silly guts, and hooves so wonderfully wide. Pinkie couldn't say anything, but she was certainly admiring Rainbow Dash's expansion. She looked better the bigger she got and the more she could rub against her.

Dash was likewise doing the same, happy to see more and more of Pinkie's body as they both grew, now taking up almost two thirds of the room, and still growing.

As the two squeaked more and more together, almost lovingly, Pinkie gained a new appreciation for Dash not as a star athlete, but as a lazy, easygoing balloon. Someone, or something, to simply rub against. If she could, she'd nuzzled Dash's latex neck and squished against her belly for all it was worth. Luckily, she didn't even have to try. The continued inflation of their bodies made it so.

The two of them slowly pressed against the two tanks even harder now. Any second now, the two of them would actually pop. The sensation of the tanks pressing against them only further increasing the pleasure they're feeling.

The squeaks. The rubber. The plastered grins. Everything was so perfect. Pinkie watched happily as Dash expanded enough to become somewhat translucent. Such a pretty balloon, light shining through a rainbow of colors as the two swam -- or rather, floated -- in pleasure.

Dash watched in similar appreciation as Pinkie turned mostly translucent herself. After a few moments, they were now pressing against not just the tanks, but the walls of the room as well.

And into each other, too. So deeply into one another. One muzzle flat against the other, hooves practically competing for room. Pinkie's gaze met Rainbow's as the pretty colors filled the whites of each other's eyes. They were stretching more and more, so beautiful. Their ponuts nothing more than untied balloon knots about at their limit.

And within just a few short moments, that limit would be passed. And in fact, Dash could mentally count down how long until that happened. Starting at 3... 2.... 1...

POP!

Cyan and rainbow and pink bits of latex rained down on the floor, and the tanks quietly hissed out the last helium they had, leaving the room still and quiet.

Even though their bodies were mostly gone besides the pieces that were left, the two ponies still remained there in spirit.

The intimacy between them practically filled the air -- or rather, what remained of what they left behind. They were alive and safe within the latex. But their minds?

Their minds were mostly gone, popped with the pleasure they had felt when their bodies did. Or at least that's what it seemed like. In fact, they were scattered among the remaining pieces, weak on their own.

Fleeting little things. Mostly the love between one another and how damn good they felt just before the pop. A vague sense of something before being a balloon, but only vague.

And if the two were found, maybe their minds and memories of what came before were restored through reassembling the pieces. Of course, that was a big if.

Indeed, in only a couple short days -- or perhaps hours? -- they vaguely felt themselves being swept up into something. A dustpan -- then tossed into the trash, to mingle nearly mindlessly with each other's flattened latex unless anypony found out what became of them. Not that they had any worries or cares about their odds. Not now, not anymore.