A Prim Party Planner's Puffy Predicament

by RadPanic

Rating: mature
Tags: DJ P0N-3, My Little Pony: Friendship is Magic, Original Character, Porn, Octavia, Fetish
Length: 12156

Octavia tries to inflate some balloons for Vinyl Scratch's birthday party… only to wind up becoming a balloon herself. [inflation fetish story]

Octavia has organized the perfect birthday party for her dear friend Vinyl Scratch. All that remains is to borrow a helium tank and fill up some party balloons. That should be easy enough—but a moment of distraction turns this simple task into a big problem that quickly grows beyond Octavia’s control.

This story is shameless inflation fetish fuel. More specifically this story features helium inflation through both ends, belly and butt inflation, spherical whole-body inflation, and immobility. If that’s not your thing, you probably won’t enjoy this.

Big thanks to:
thefurryrailfan for cover art, the initial idea, help with proof-reading and editing, and letting me borrow his OC,
Learn for Life for help with proof-reading and editing,
MintyCandy, Lupin Quill and wydzard for letting me borrow their OCs.

Tip jar: https://ko-fi.com/radpanic

Published 2020-10-24 02:30:01 UTC
Last updated 2020-10-24 02:30:01 UTC

Perfect Party Imperiled by Pesky Problems

Octavia was in control. So much so, she barely even flinched as Pinkie Pie leaned close, dangerously close, and said, “Are you suuuuuure?”

Outwardly unperturbed, Octavia answered, “Yes, Pinkie. I’m sure.”

“But are you sure sure?”

“Listen.” Octavia lifted one eyebrow half an inch: that expression would have made any pony from the Canterlot Symphony Orchestra cower in fear, but unfortunately its severity was completely lost on Pinkie. Octavia continued, “I want to rent two of your helium tanks, one jumbo-sized and one medium. And no amount of second-guessing from you will change my mind.”

“Okay,” Pinkie answered, tilting her head until it was completely upside-down. “But why?”

Octavia smiled as she gave her rehearsed answer. “I’m arranging a birthday party for a very dear friend, so I want to make sure it’s perfect. And that means bringing backup helium tanks to ensure I can inflate enough balloons for her.”

“Oh, oh! Why don’t—mmmph!”

Octavia placed her hoof over Pinkie’s mouth, cutting her off, then continued. “Said friend also called me a stick-in-the-mud and said—and I quote—’Tavi, you wouldn’t know a fun party if it puked on your hooves. So it’s a matter of pride that I organize this party myself and prove her wrong. Surely you understand?”

———

Minutes later, Octavia trotted down Ponyville’s main street, towards the home she shared with Vinyl Scratch. She passed dozens of ponies, but none of them bothered to ask why she had with her a cart with two helium tanks—one jumbo-sized and one medium—so her rehearsed answer about the birthday party went unused. That was for the best, as Octavia preferred to lie as little as possible.

It was only a lie of omission, at least. She really did need the helium to set up a surprise party for her housemate. She’d just neglected to tell Pinkie her plans for after the party.

The illicit thrill of Octavia’s plan brought a flush to her face, but it didn’t look out-of-place in the October chill—so it, too, drew no comment from passers-by. Octavia was in control.

Approaching her front door, Octavia spared a glance back at the smaller of the two tanks. As soon as Vinyl’s party is ready, she thought, I’ll “misplace” you in the basement. We’ll have our fun for a week or so, then I’ll “find” you again and return you to Pinkie. It’s the perfect crime.

She opened the door and quickly surveyed inside, confirming the house was empty. Vinyl was still away—purchasing a new mixing board or subwoofer or whatever as a birthday treat—so Octavia had the place completely to herself for now. She pulled the helium tanks inside and closed the door behind.

The shared living room had already undergone a minor transformation. White and gold streamers stretched across the ceiling on both sides, and a similarly colored banner proclaimed birthday well-wishes; Octavia was quite proud of finding colors that complemented both the subdued earth tones on her side of the room, and the garish purples of Vinyl’s side. Below, all the furniture had been pushed to the walls—as had been the instruments like Octavia’s piano and Vinyl’s rack of keyboards—leaving a wide open space in the center for guests to mingle.

On the far wall, near the dividing line, was a table stacked high with tasty but healthy snacks. Next to it, Octavia had set up the phonograph, along with a carefully curated collection of LPs: traditional dance music from every corner of Equestria, in case anypony felt like cutting the rug, and cool jazz and pleasant chamber orchestra pieces for the rest of the evening. And adjacent to the phonograph was one last table with several board games, a mix of trivia and strategy titles to provide both entertainment and mental stimulation.

Octavia left the smaller helium tank by her couch, then wheeled the larger one closer to the center of the room. As she walked, a crunching underhoof reminded her there was, unfortunately, still more cleanup to be done. Discarded food and drink containers littered the floor on Vinyl’s side, but there was still plenty of time to dispose of them properly. Later, of course—it was balloon time now.

Octavia found the ideal spot to set up the jumbo-sized helium tank, close to the center of her own side. And now that she was alone with it, able to properly admire it, she had to admit that Pinkie Pie had gone above and beyond: this tank was tall and wide enough, it could have fit Octavia herself inside, easily. She placed a hoof on its side, and felt the smooth, cold metal against her frog—lighting up her imagination with thoughts of the sheer volume of helium on the other side of that shell.

Octavia shook her head and snorted. She pulled her hoof away, then grabbed the first packet of balloons and went to work. Taking her seat on the floor next to the tank, she popped the first balloon onto the nozzle. She squeezed the trigger, filling the balloon to a satisfactory size, then yanked it off and tied it shut before any gas could escape. Once she’d affixed a string around to the end, she released the balloon to bob at the end of its tether. Then Octavia repeated the process with a second balloon, and a third—gaining speed as the motions became more familiar. Her dextrous hooves, which had danced over the cello and brought the music of Beethoofen and Maredi to life countless times before, now played a divertimento of squeaking rubber and hissing helium.

After filling a few dozen balloons, Octavia shifted slightly in place. Sitting directly on the hardwood floor would become uncomfortable soon enough, so she looked around for a pillow to use instead. Her gaze fell upon the medium-sized tank of helium. Octavia blushed slightly as she considered it—obviously, the tank wouldn’t be as soft or comfortable as a cushion, but it would be pleasurable in its own way.

Octavia gave one more furtive glance around the room, before pulling the tank towards her, and lowering her backside onto it. As her hind legs straddled its sides, the cold metal’s touch sent a pleasant shiver up her spine. Octavia rested her full weight on the tank; her derrière’s lean cheeks squished slightly against the tank’s smooth curvature.

Lovely, Octavia thought, shifting her weight slightly atop the canister. Now that I’ve got that sorted, hopefully there’ll be no more distractions.

Back to work she went—once again filling the balloons with helium, and filling the room with creaks, squeaks, and hisses. As she slipped each balloon onto the nozzle, she leaned forward, pressing her petite teats and the bottom of her lithe belly against the steel tank below. Then as she knotted and strung up each balloon, she leaned back, placing her weight again on her posterior. Forward and back, forward and back she leaned—the insides of her haunches brushing against the cold, smooth steel over and over again.

“Mmm, yes…” Octavia said, as she released another balloon to join its inflated brethren. Squeezing the tank between her hind legs, she let her mind wander, imagining the incredible pressure of all the helium inside that metal cylinder—and the effects it could have on a pony’s body. As she filled the next balloon, she imagined it was actually a small pony, a white unicorn with an electric blue mane. And then the balloon after that, in her mind’s eye, was a gray earth pony with a G-clef cutie mark; each rubbery squeak was a giggle of pleasure as the tiny pony swelled larger between Octavia’s hooves. The little pony rubbed her own belly as it puffed out twice, then three times its usual volume—until air filled all her legs, and they swelled up too stiff to do anything but stick straight out. She greedily sucked down more and more helium, filling her belly five, then six times larger than before; her shoulders and haunches sank into that gray orb as it grew even larger. And as Octavia watched the little pony grow and grow in her hooves, she kept shifting her own flanks slightly atop the smaller helium tank, holding the cold cylinder tightly with her haunches. The imaginary pony finally expanded to ten times her old volume—her body nearly spherical, her legs sunken into her puffy sides until only the hooves poked out—so Octavia pulled the tiny pony off the nozzle and tied her muzzle shut with a string, ensuring no air escaped from her blushing face.

As that balloon drifted up, Octavia reached for the next, only to find the packet was completely empty. She blinked and glanced up at the huge mass of balloons she had already filled. Sure enough, she’d inflated fifty already, more quickly than anticipated.

My, she thought, fifty balloons is more than I expected. This might already be enough for Vinyl’s party. Then she gave the tank between her haunches another squeeze, the cold steel’s touch sending another shiver up her spine. She glanced back up at the inflated balloons, and in her mind’s eye she saw a whole herd of tiny ponies—white unicorns and gray earth ponies—each swollen with helium into a ball with puffy hooves poking out from their inflated sides. They squeaked and squealed through muzzles tied shut with strings, trying to tell Octavia how good their puffed-out bellies felt, how she ought to send more friends to join them.

Definitely not enough balloons yet, Octavia thought. This party needs more.

The other balloon packets were out of reach, forcing Octavia to stand up. Vinyl deserves the very best, after all, she thought, as she grabbed the next pack with her mouth. Returning to her place by the jumbo helium tank, she glanced up at her herd of inflated ponies. More squeaks came from the floating bunch as they tried to cheer, tried to wave their hooves in celebration—but with their legs swallowed by their own bloated bodies, each attempt to move just made the ponies bob in the air and brush against their neighbors. Octavia gave them a smile as she sat down again on her impromptu perch…

...and she missed, instead dropping her rear onto the helium tank’s business end. Octavia’s eyes widened as the nozzle slid right up her backside. “Oh!” she yelped, dropping the balloon packet, and instinctively clenched her rump—her thin cheeks squeezing the nozzle and trigger. With a familiar hiss, the helium in the tank began blowing into Octavia’s backside.

“Oh…” Octavia said, as her ears folded back and the blush returned to her cheeks. “Oh my.”

Her stomach swelled out an inch, then two, as more and more helium pumped into it. She placed a hoof to her belly, another shiver running up her spine as she felt how that belly stuck out farther than before. Her formerly fashionably flat midriff had puffed out into a proper paunch—and it was still growing. The soft flesh near Octavia’s navel pressed back against her hoof, its pressure increasing by the second.

“How embarrassing,” she said, with a quiet chuckle. “And what if somepony were to walk in right now, and see me in this position? Imagine what sort of ridiculous misconceptions they’d form about me.” But a glance at the door confirmed nopony was coming; she was still alone for now.

And for now, there really wasn’t any harm in staying right where she was just a little bit longer, was there? Octavia was in control. She knew her limits from past experience—more experience that she would ever admit in polite company—and at her current size she could still deflate back to normal in time for the party. She closed her eyes. She could afford to enjoy her current position for a few seconds more, before getting back to work—to savor the sensation of her stomach stretching to fit all that gas, the bracing coldness of the helium swirling around inside her, the pleasant pressure of her belly bulging against her own hoof as it expanded, the way her puffed-out paunch jiggled each time she rocked back and forth atop her perch…

Wait, Octavia thought, jiggle?

Her eyes shot open, and she looked down. Her brand-new gut looked as though she’d swallowed a throw pillow, and it swelled an inch larger as she watched. Oh dear, she thought. How long did I zone out? She clapped her other foreleg against that belly and squeezed with both hooves, as if she could force the helium back out. But all this did was squish her hooves into her own pillowy softness; her stretchy stomach jiggled even more as it pushed back, enveloping her hooftips in its continued growth. With every wobble, that belly squeaked quietly, and the blush deepened on Octavia’s cheeks at the sound.

It’s not too late! Octavia thought. Deflating to her normal size in time for the party was out of the question now, but she could at least shrink down to a size close to normal—as long as she removed herself from the nozzle, now. The other guests probably wouldn’t even notice the difference. Octavia was still in control, even though her belly was the size of a half-inflated beach ball and still growing, squishing against her forehooves as it expanded a few inches more—even though gas was beginning to flow into her rump, expanding it as well. She just needed to stand up, get her rear end—already a few inches wider than normal—off the helium nozzle, right now.

Octavia shook her head and snorted. She removed her forelegs from her expanded gut—which jiggled once again at the motion—then planted all four hooves on the floor, pressing her oversized belly against the tank below, until it squashed out a few inches to both sides. Finally, she stood up.

But the helium tank came off the floor with her, the nozzle still firmly planted in her rear. Octavia boggled at the sight, allowing the helium to rush into her belly and butt for a few seconds more, before she chuckled. “Of course,” she said. “Silly me, thinking it could be that easy…” She exhaled and relaxed her rump, loosening her buttocks’ grip on the helium nozzle. But that had no effect either—her rump cheeks had swollen enough to grasp the nozzle of their own accord, so the tank remained tightly stuck, and continued pumping gas into her overfilled stomach and backside. Octavia chuckled again, but her ears folded back, and sweat appeared on her brow. She wiggled her rump back and forth, then shook it forcefully—but all that did was slap her cheeks together and jiggle her swollen stomach, as the continued flow of gas filled all her curves a few inches larger. By now, her rear was like a pair of watermelons, and her helium-filled gut extended below her stifles and bulged out to the sides far enough to press against her legs each time it swung side-to-side.

With a snort and a scowl, Octavia shook her backside harder, to no avail. She crouched with her forelegs, until her chest was just inches from the floor, and stuck her rump high in the air, continuing to shake those still-expanding cheeks all the while. “It’s a good thing Vinyl isn’t here to see this,” Octavia said, the blush deepening on her face as she waved her tail back and forth. “I can only imagine what sort of off-color jokes she’d make…” Her bloated belly squished underneath as she crouched—squeezing several inches out to each side, bulging farther as the helium continued to fill her—and it jiggled in time with her shaking backside. With every wobble of that inflating gut, her elbows poked a little deeper into its swelling sides. Still, no matter how much she wiggled her backside, the helium tank refused to budge. If anything, as her cheeks grew larger and more bulbous with every passing second, the tank slowly sank deeper between them.

And with every passing second, every cubic inch of helium filling her stomach and rump, Octavia’s hopes of passing for normal at Vinyl’s party slipped further and further away. She could deflate a few inches between now and then, but that wouldn’t be nearly enough. Somepony was almost certain to notice how big and round she was—at least one of the guests would stare awkwardly, and Vinyl was all but guaranteed to crack dumb jokes about her. If anypony asked, at least Octavia could pass off her enlarged belly as the result of an excessive lunch—assuming, of course, she could dislodge the tank before she grew much bigger…

Octavia snorted and gave one last frustrated shake, before standing back up. “Oh, helium tank, you’re really becoming quite a bother,” she said, glaring at the offending tank beyond her still-widening rear and even wider middle . “If you know what’s good for you, you’ll get out right now, before I really get cross.” But the completely inanimate metal cylinder just continued pumping helium up Octavia’s backside, heedless of the warning—filling her gut up to the size of a yoga ball, and then larger. Even though she was standing again, her ballooning belly was only a foot away from touching the floor—and that gap slowly shrank as her gut continued inflating. It swelled wider as well, already approaching twice its normal width; it pressed against the insides of her legs as she stood, bulging through the space between those limbs.

“Fine,” Octavia said. “You’ve given me no choice.” She raised one hind leg—in the process, wobbling her inflated haunch and squishing her stifle farther into the pillowy softness of her stomach—and gave the helium tank a mighty kick. Or rather, she gave the air in the general vicinity of the tank a mighty kick. Octavia snorted and kicked a few more times, with her right hoof, then her left, then her right again, but she whiffed each time. With every failed kick, she turned a few degrees, unintentionally rotating towards the other, jumbo-sized helium tank. And all the while, her belly wobbled and her rump jiggled at every movement, both inflating larger still.

After that last kick, Octavia stumbled but caught herself before she fell. Simply standing was becoming more awkward by the second: her swollen belly was pressing harder against the insides of her legs, the force increasing slowly but surely as that gut grew ever larger. What once had been her normal posture now required Octavia to squish her limbs several inches into her belly’s inflating sides. That thick balloon of a stomach—over twice as wide now, and just six inches away from reaching the floor—squeaked and jiggled some more as Octavia raised her rear hoof for one more kick.

The kick connected—only a glancing blow, but enough to jostle the tank slightly. But Octavia’s smile quickly fell once she heard the Clunk! of a hunk of metal landing on the wood floor. It was the helium nozzle’s trigger. And with the trigger broken off, the valve now opened all the way, pumping helium up Octavia’s backside almost twice as quickly as before. She folded her ears back and gulped, while her belly swelled even larger—squishing even further around the sides of her legs and rapidly closing the distance to the floor. She kicked at the tank a few times more, but each kick went wider than the last, just as Octavia herself was growing wider by the second. Her belly had bulged thick enough to force her legs apart, and the further she inflated, the harder it would be for her to reach the tank with her hind hooves.

Octavia no longer had to imagine what the pressure in that tank could do to a pony’s body; instead, she found herself imagining how she could possibly avoid complete embarrassment at Vinyl’s party. Passing for normal was a long-gone dream, slipping further from reach with each new cubic inch of helium pumped into her. Everypony was going to notice her new size; Octavia was going to spend the party apologizing profusely for accidentally bumping guests with her huge new belly and ponderous rump. And if anypony were to ask, she couldn’t even pass off her new girth as overeating: she was too light, too perfectly round to be anything but a gas-filled balloon. Octavia would have to admit there’d been an accident with a helium tank, and simply omit a few details leading up to said accident. And that was the best-case scenario; if she didn’t dislodge the helium tank soon…

Octavia shook her head, dismissing that chain of thought. She was going to free herself! And then finish the party preparations afterwards! She was still in control.

And then the lowest edge of her belly brushed against the floor, the sensation jolting Octavia back to reality. Her stomach was still swelling larger, and her rear wasn’t far behind. Realizing that further attempts to kick away the helium tank would be a fool’s errand, Octavia instead extended her foreleg back that direction. Twisting to reach back, she pressed her shoulder into the top of her inflated stomach, while her cannon squeezed against her puffed-out haunch. As she squished into the grey softness of her own inflating body, her hooftip brushed against the helium tank’s side—almost enough to get a grip, but not quite. All the while, she jiggled and shook at the slightest movement: her thick, bulbous rump cheeks slapping together, and her huge stomach fully resting on the floor. Octavia gritted her teeth and strained to reach back farther, squeezing inches deeper into her belly and backside—while they squished back with ever more pressure, bulging further around her leg as they filled with more and more gas. As her hoof crept closer and closer to a proper grip on that metal cylinder, her belly also crept across the floor inch by inch, spreading to the sides and pushing her legs further apart now that there was no more room to expand downwards.

Finally, Octavia clamped her hoof against the tank. “Ha!” But before she could do anything more, her other forehoof slipped off the floor—pushed too far by her belly’s continued expansion. With neither forehoof on the ground, she dropped a couple inches, while the squishy cushion of her gut bulged beneath her even further outwards. And then Octavia rolled slowly forward on that overfilled stomach, her huge rump jiggling as it lifted into the air—while her head angled down, towards the other, jumbo-sized helium tank.

Octavia’s eyes widened as her face drew inexorably nearer to the helium nozzle. She waved her forelegs, flailing in a desperate attempt to make herself roll somewhere else.

“Oh nooooooooooooooo—Oomph!” Her open lips popped onto the nozzle, and the first blast of helium rushed into her mouth, then down her throat.

“Hrrm! Hrrmmph!” Octavia tried to protest, through cheeks that were beginning to puff out. With helium pumping into her from both ends, the gas was now filling her whole body, not just her belly and rump. Her sharp shoulder blades grew blunter as her shoulders rounded out; the bumps of her spine shrank as her back began to expand. “Mmrrph!”

Octavia planted her forehooves on the floor again, then her rear hooves, and stepped backwards, away from the helium tank—or rather, she tried. Her hooves slid across the hardwood as she futilely tried to pull herself off the nozzle that was relentlessly filling her with more helium. With every attempted step, her legs squeezed deeper into her expanding belly—that pillowy gray gut bulged around her limbs so far, it nearly enveloped them. And the growing outward pressure of her stomach’s expansion made it harder with every passing second for Octavia to keep any grip on the floor at all.

“Hhrrmmm…” Octavia groaned, her cheeks puffing up to the size of baseballs. She tried once more to pull herself off the helium tank, and suddenly found her hind hooves kicking the empty air. “Mmmph? Mmrrph!” Her eyes widening, she tried to reach the floor with her hind legs—but her belly’s expansion had lifted her backside too high. Her hooves just dug into the back of her gut with each attempt to walk, while her ballooning stifles squished back against her belly’s expansion, squeaking like rubber, jiggling and rubbing together with Octavia’s every movement. Her rump cheeks were individually wider than the average mare, while the huge cushion of her gut was three times wider, and still growing.

“Mmrrmmrrmmph!” Octavia’s forehooves pitter-pattered on the floor as she desperately tried to scoot herself away from the oversized tank with only those two legs. The overfilled gray balloon of her stomach shook with every movement—and wobbled and squeaked each time her elbows squished into its sides—but Octavia didn’t budge from her place at all, and just inflated even larger. “Mmmmrrrr…” she said as she tried to step back once more—and when her right hoof left the floor, it didn’t come back down. “Hrrrrrr!” Octavia stretched that leg, trying to reach the floor again, but only succeeded at squishing it several inches into her belly’s side. And then her left hoof rose from the floor as well, stranding her atop her belly’s continued expansion.

“Hhhmmph! Mrrrrhhh!” Her pupils shrinking to pinpricks, Octavia waved her forelegs in the direction of the floor, which her belly continued lifting her away from, inch by inch. “Hhrrrmmp!” she tried to protest as she was raised higher and higher by the cushion of her gut—large enough to fit two party guests inside, and still filling even larger. “Mrrrrpph!” She planted her forehooves on the helium tank and tried to push herself away, but her lips remained firmly stuck on the nozzle. “Hrrrrrrrr…” Groaning, she screwed her eyes shut and pushed even harder—and succeeded, rolling backwards a few inches on the huge balloon of her gut. Yet the vacuum seal between Octavia’s mouth and the nozzle remained intact. Her snout stretched like rubber as she pulled away, allowing the continued flow of helium to keep inflating her even larger.

“Mmrrrrrr?” Octavia opened her eyes again and boggled at her own face’s elasticity, mumbling through cheeks filled as big as grapefruits and still growing larger. She pushed further against the helium tank, her forelegs giving off rubbery squeaks at the motion. Gas was beginning to fill her limbs now: her forelegs were already a few inches thicker than normal, and her shoulders were puffing up into smaller balloons, affixed to the enormous balloon of her torso. Her hind legs thickened with helium as well, and those limbs felt ever-so-slightly stiffer as they gave another futile kick, her hooves squishing into the back of her belly. Her rump and haunches, swollen as big as dual exercise balls, jiggled and slapped against each other at the motion.

But the further Octavia pushed herself away from the tank, the more her face stretched, and the more helium rushed between her lips to inflate her even larger. Her belly was now itself as tall as a normal pony and four times as wide, and still spreading across the floor, inch by inch, as it filled ever larger. Octavia rode its continued inflation higher and higher. Behind her, the smaller helium tank—still firmly wedged between her expanding buttocks—scraped its bottom edge against the floor one last time before it, too, was lifted into the air by her continued growth. Its smooth metal side squished slightly into the back of her huge belly, as it continued pumping helium to fill that belly even larger.

“Hrrmm?!” Startled by the sensation of cold metal against her gut, between her thickening hind legs, Octavia tried to glance back at the source. But with her lips still stubbornly stuck to the helium nozzle, simply looking past her own puffy shoulders proved impossible. She pushed further with her forelegs—fighting their growing stiffness as they swelled wider with every passing second, and fighting the pressure from her inflating shoulders to splay those legs out to the side. At last, she extended her forelegs all the way—and still her snout stretched her entire arm-length, while her lips remained vacuum-sealed around the nozzle, permitting the helium to continue pumping into her, to fill her larger and larger.

Octavia’s shoulders gave rubbery squeaks as they inflated, growing more doughnut-shaped by the second. They pushed ever more firmly against her forelegs the larger they filled; those forelegs trembled as Octavia fought to keep pushing the helium tank away. “Mrrm!” she grunted, furrowing her brow. “Mrrrm! Hrrmm!” As all her limbs puffed up even further with every passing second, Octavia still resisted the pressure from her own treacherous, expanding body to spread her forelegs out. All the while, the cushion of her gut expanded even larger—five times her normal width now, and still spreading inch by inch across the floor.

The twin globes of her swollen rump jiggled merrily as they rode her belly’s expansion higher above the floor. Those haunches and cheeks, filled to the size of bean bag chairs and still growing, squeaked as they brushed against each other, as their stifles squished back against her expanding belly, and as the small helium tank sank deeper between those buttocks. Then, on either side of the small tank, her rear hooves gave one last kick before—Fwoomp!—her hind legs inflated too thick to move. Nearly a foot wide, those puffy limbs stuck straight out beneath the still-swelling balloons of her haunches.

“Mmmrrh?” Octavia wondered, once again futilely attempting to glance at her own backside. But just as her attention drifted away from the larger helium tank and her own forelegs, she lost control over them—Fwoomp! Fwoomp!—and her puffy limbs whipped out to either side, sticking straight out. Her stretched muzzle finally contracted—Whack!—smacking Octavia’s face into the tank. She rebounded from the collision, her eyeballs spinning inside their sockets. Her forelegs, swollen twelve inches wide, wobbled involuntarily from the sudden movement, squeaking as they brushed against her similarly shaking belly.

And then the giant helium tank’s trigger fell off, broken by the recent collision with Octavia’s face. It bounced off the front of her inflated belly and hit the floor with a metallic clunk!—snapping her back to attention just as the helium flow sped up to twice, three times faster than before. “Hmhmmmhmmm…” she whimpered between cheeks puffed out as large as grapefruits, as she stared down at the nozzle pumping more and more gas into her. Unconsciously, she tried to reach forward once more to push the tank away—but her swollen legs could only wiggle about a foot in any direction. And even that range of motion was slowly shrinking, as her legs had begun to sink into the inflated doughnuts of her shoulders.

Her legs swollen too stiff to move, and stranded atop a belly seven times wider than normal and still growing, Octavia was truly immobilized and helpless. “Mmmmhh…” She folded her ears back, until— Fwip! Fwip!—they inflated as well, yanking even that small degree of freedom out of her grasp.

Octavia wasn’t in control anymore. And as she inflated even larger—helplessly filling with gas from both ends—she couldn’t help but wonder in the back of her mind at what exact point this whole scenario had blown up too big for her to handle. When she had filled up too big to reach the floor with her hooves? When she got her mouth stuck on the larger tank? When she accidentally sat on the first tank and took too long to stand back up?

Perhaps at the very beginning, when she rented the extra helium tank from Pinkie Pie? Had her mastery of the situation just been an illusion all along?

Octavia sighed and rolled her eyes. Whatever mistakes she identified by hindsight, it made no difference to her current situation. No mental flagellation could change the fact that she was more balloon than pony now, filled with at least a dozen times her own volume in helium—and with more gas pumping into her by the second. That ample belly was three times Octavia’s normal height and eight times her width, and rapidly approaching nine times. On the ever-widening sides of her ballooned torso, her puffy legs had already sunk halfway into the inflated doughnut shapes of her shoulders and haunches, and with every passing minute they disappeared a little further. Octavia was well and truly stuck at this point. The only thing she could do anymore was hope somepony came along soon to free her—and until then, she’d just continue gulping down helium and inflate even further.

And since getting out of this predicament was completely out of Octavia’s control, why not simply enjoy it while it lasted?

The thought popped unbidden into Octavia’s mind—she blushed harder than ever, the tint even spreading to her puffy ears—but she couldn’t think of any good argument against it. And there was plenty to enjoy here, more than she would ever admit in polite company. As she grew to accommodate the ever-increasing volume of gas inside—expanding to eleven times wider than normal, and then even larger—it felt like the pleasant burn of a post-performance stretch, but spread over her whole body. In contrast, the helium rushing into her from both ends was pleasantly cool as it filled her to increasingly enormous sizes. As her immobilized legs sank deeper into her sides, they fit into the puffy doughnuts of her inflating shoulders and haunches as comfortably snug as her cello inside its custom carrying case. Likewise, her neck formed a thick collar as it swelled with gas—and where it brushed against her ears or bulged around her puffy cheeks, the touch of her own immaculate coat was soft as velvet.

And the larger Octavia inflated, the better those sensations felt, as her stretching skin grew ever more sensitive. Filling with over fifteen times her volume in helium, her gut spread further and further across the floor. Every square inch she covered was a new note in the sensual symphony playing across her ballooning stomach. Octavia’s ever-growing volume already covered half the floor space on her side of the room, her sides squishing against the coffee table and brushing against her couch, the furniture playing against her expanding body like master soloists. And as helium continued pumping into her, she crossed the line to Vinyl Scratch’s side, where the cool, smooth tile against her inflating body made a pleasing countermelody to the hardwood’s texture on her own side. With her belly ballooning and spreading even further, discarded fast food wrappers crumpled and empty energy drink cans flattened beneath its relentless expansion—each one a cymbal crash of pure joy in Octavia’s brain.

Meanwhile, perched atop her blimpy belly, Octavia’s super-sized rump expanded even further. Both cheeks were individually larger than an adult pony and still growing, all the while jiggling and squeaking against each other merrily. As she inflated ever larger, with her head held in place by the helium nozzle, her backside angled upward. Her ample posterior lifted higher and higher, pushing aside the decorative streamers with its still-ballooning cheeks. Of all the pleasures Octavia would never speak of in polite company, the most unspeakable was the delightful wickedness of possessing a derrière this huge, raising it towards the sky as if presenting herself to an unseen lover—all the while reveling in every touch as her cheeks’ bounced against each other, against the the back of her belly, in their uncontrollable wobbling.

Surrendering to this new universe of pleasure, Octavia allowed her eyes to roll back—until the fifty party balloons, still tied to the giant helium tank’s side, caught her gaze once again. In her mind’s eye, they were still a flock of tiny inflated mares, only now their ranks consisted entirely of gray-coated earth ponies with clef cutie marks on their puffy posteriors. “One of us! One of us!” they squeaked at her with tiny, helium-distorted voices.

Octavia laughed into the helium nozzle still pumping gas into her mouth, though her own voice was little more than a squeak, too.

“One of us, Octavia! Knock, knock! Knock, knock, knock!”

“Mmmrrph?” Octavia said, her muffled voice echoing through cheeks swollen as large as pumpkins. She tried to quizzically tilt her ears, but those triangular balloons atop her head remained unresponsive.

“Knock, knock, knock!”

Knock knock!

Snapping back to reality, Octavia finally realized that the knocking wasn’t just her imagination, but the actual sound of somepony’s hoof rapping the front door in real life. It clearly wasn’t Vinyl Scratch at the door—she’d have simply waltzed in without knocking—so it must have been one of the party guests. A mess of thoughts bubbled up through the haze of pleasure in Octavia’s mind: So embarrassing—can’t let them see me like this! But they can help free me! But this feels so good—don’t want it to stop! But I gotta save Vinyl’s party—there’s still time!

So when Octavia tried to call out to her guest and only managed a squeaky “Hhhhhmmmmmmrrrgh…” even she wasn’t quite sure what it was supposed to mean.

It didn’t matter, anyway. Her feeble voice was barely audible over the fugue playing upon her body’s continued expansion: the brushing as her belly spread ever farther across the floor; the scraping as couches and tables were pushed aside by her relentless growth; the discordant bwooong of the piano keys her belly pressed down as it spread; the rubbery squeaks as her legs sank up their pasterns into her inflating torso, as the fat collar of her neck spread over her crown and squished around her puffy cheeks; the wooden groans as her enormous posterior bulged against the ceiling rafters, as her stomach squished around furniture that wouldn’t budge any further.

Another knock sounded from the door, almost teasing Octavia. The door was unlocked—hardly anypony locked up in this town—so if she could just let the visitor know she was in here, nothing was keeping them from entering and freeing her. Again Octavia tried to call out, but even with her resolve strengthened, her voice was barely louder than before. “Mmmrrrhh! Hhnnnmm mmpphh mmmnnnn!” Her puffy cheeks wobbled at the effort as they filled even larger—in spite of the squeezing pressure on them, as her head began sinking into the spot where her bloated neck had merged with the greater curves of her torso. Octavia’s cheeks were twice as big as her skull; her face was easily wider than her own backside had been just an hour ago. And the helium nozzle remained firmly stuck between those gray balloons, pumping still more gas down her throat, filling her enormous belly with twenty times her own volume in helium, and still counting.

———

Outside the musicians’ cottage, an orange pegasus knocked on the front door once again. “Strange,” he said. “Very strange.”

His partner, a white unicorn, tilted his head slightly. “Did we misread the invite and show up too early?”

“I doubt it,” the pegasus replied. “And if we did, it wouldn’t explain her.” He gestured at the footpath, where a third pony, a yellow-green pegasus mare, was approaching.

“Hey, Twintails, hey, Minty,” the newcomer said. “What’s going on? Is Octavia not home yet?”

The unicorn, Minty, shrugged. “Looks like it, but—”

“But it makes no sense!” Twintails interrupted. “Octavia’s the personification of professionalism and punctuality. It’s completely unlike her to be tardy to an event she herself organized.”

“Yeah, now that you mention it, this is kinda weird,” the mare replied. “Maybe she’s in the back of her house and can’t hear us? If we knock louder, maybe we’ll get her attention.”

Twintails and Minty exchanged glances, then grinned back at the mare. “Knock louder?” Twintails said, stepping into place at her side.

“What an excellent idea, Radicchio!” Minty took the mare’s other side.

The pair suddenly grabbed Radicchio and hoisted her off the ground. Holding the pegasus tightly, they rushed towards the cottage entrance. As Radicchio found herself speeding head-first towards the door, all she could say was “Whaaaaaaaaaa—”

———

There was another knock at the door, louder this time.

“Mmrrph! Mmmrrrph!” Octavia tried to call, but her voice was still drowned out by the noises of her continued inflation. Her legs had sunken far into her torso, leaving only her hooves visible, barely able to move an inch in any direction—but she unconsciously tried to wave and kick anyway, which just made her balloony body wobble harder, adding more squeaks to the symphony of her continued expansion. She even jiggled hard enough to jostle the helium tank, shaking the inflated balloons still tied to it. The squeaks of those balloons rubbing against each other, and against Octavia’s swelling shoulder, still sounded in her mind like laughter from a herd of tiny earth ponies. And with every laugh and every jiggle of her belly, her backside bounced as well. Already that rump was so enormous that the G-clefs on her haunches stretched taller than an adult mare—and still it filled even larger, squishing against her gut below and the ceiling above, stretching the party streamers across the absurd curves of those cheeks. It wasn’t just Octavia’s overfilled rump pressing against the ceiling now; the more she expanded, the more of her rounded back squished against the wood above, bulging around the rafters to fill every available space. With nowhere to go vertically, she grew still faster to the sides, spreading over even more floor space as the helium relentlessly filled her. She’d already covered nearly all of her side—squishing over her couch and coffee table, enveloping the piano with her bloating torso—and she filled just over half of Vinyl’s side.

“Hhhrrrmmm!” Octavia continued calling, trying to speak against the continued flow of helium. The nozzle between her lips vibrated with her voice, and the smaller tank in her backside bounced with every wobble of her inflating body, sinking deeper and deeper between those expanding rump cheeks. All the while, both tanks pumped more and more gas into her—thirty times her normal volume now, and with no end in sight.

———

Outside, more party guests arrived. Already, there were half a dozen ponies just standing there and watching as Twintails and Minty continued knocking Radichhio’s head against the door.

“Wait! Wait!” Radicchio cried out. Miraculously, the other two actually did stop long enough for her to continue. “I’m a pegasus! I’m too light to make a good door knocker! Wouldn’t an earth pony be better suited to this kind of thing?”

Twintails and Minty glanced at each other. “You know, you’re right,” Minty said. They set Radicchio down on the ground…

...only for two earth ponies—a teal mare with a curly mane, and a stocky green stallion with a goatee—to take their place and grab her once again. Radicchio had just enough time to gulp before they swung her at the door another time…

———

Now the knocking was so loud, it sounded like the door was in danger of falling off its hinges.

“Mrrrr—mmmmm…” Octavia’s further attempts at speech turned instead into a pleased moan, as something new brushed against her expanding sides, then pushed back against her continued growth, and it felt so good. The sensation spread over her torso, and Octavia finally realized: it was the walls. She’d inflated so far, she was squishing against all three walls on her side of the room. At the rate the helium was filling her up, it wouldn’t be long before she reached the walls on Vinyl’s half of the room as well...

Octavia’s eyes widened as she realized the implications of that. “Hhhrrrrrmmph!” she protested, even as she helplessly gulped down yet more gas. Her hooftips waggled futilely one last time, then sank completely into her torso’s relentless expansion. The inflated doughnuts that swallowed them—that had been her shoulders and haunches—were now taller than an adult pony. Her belly was a squashed globe that covered four-fifths of the floorspace, bulging over the tables of board games and healthy snacks, squishing around Vinyl’s mixing deck and garish pleather couch. Her rump cheeks were individually larger than that couch—together, that posterior was bigger than anything for sale at Sofas & Quills—and her cutie marks stretched with them, already twice as tall as Octavia herself had been. Now, only a few feet of space separated one of those cheeks from the front door; as Octavia’s belly and backside bloated wider and wider, that distance inexorably shrank.

And the more of the room Octavia filled with her expanding body, the harder it was to remember why, exactly, she had wanted this to stop. Every new square inch of floor, wall, or ceiling that her body squished against, was another jolt to the pleasure center of her brain. At the spots where her belly bulged over furniture—or where her rump squeezed between the rafters and stretched the party streamers, or even where the crevice between her neck roll and her inflated right shoulder trapped the party balloons against the wall—all those objects pressing into her swollen body felt better than a massage from angel wings. In comparison, her best friend’s birthday party seemed to grow less important by the second. Much like her own inflating body spread over every object in the room, the sheer sensual pleasure was a mental landslide, slowly but steadily burying all her worries about the unfinished party preparations.

A few more knocks at the door cut through Octavia’s mental haze. When she attempted to reply—“Hmmhhmmhmmmmmmm…”—her voice came out as something between a whimper and a moan. All the while, the nozzle between her lips continued pumping helium into her, forty times her volume and more, while her relentlessly expanding body threatened to fill every cubic inch of the room.

———

“Hey, Linework? Lupin?” Twintails said. “This isn’t working,”

Linework and Lupin Quill, the two earth ponies, ceased beating Radicchio’s face against the door. The unfortunate pegasus had twinkly stars circling around her head, which was smashed flat as a pancake.

“There’s no way she would’ve just ignored this racket,” Twintails continued. “I guess she really isn’t home after all.”

“Yeah…” Lupin said, unceremoniously dropping Radicchio. “Hey, what if she’s expecting us to go in, and left us a note inside?”

All the other guests murmured their agreement at that. There were just over two dozen by now, gathered in a half-circle around the front door. Emboldened, Lupin stepped up to the door and grabbed the handle. “It couldn’t hurt to check,” he said.

Lupin opened the door—about two inches, before something blocked it. Furrowing his brows, he pushed a little harder, and the obstacle gave another inch before pushing back. Peering through the crack, he couldn’t make out what the obstacle was: he just saw something uniformly gray, then the door was pushed shut. “Huh,” he said.

When he tried to open the door again, it wouldn’t even budge.

———

Something pressed into one of Octavia’s rump cheeks, making a small but distinct line of pressure, miniscule against the glorious curves of her expanding backside. In the back of her mind, she knew this was the door squishing into her, that somepony was finally trying to enter the house—and obviously not succeeding. With a delicious thrill, she felt her rump push back against the door and close it tightly. Then those curves squished past the door frame, spreading inch after inch across that wall, as the flow of helium continued filling her to ever more absurd sizes. She was big enough to press against all four walls now, and still she continued inflating even larger.

Octavia had thought herself completely immobilized before, but now she discovered how naive she had been, as she found it was possible to be even more trapped inside her own body. Her legs were completely swallowed by her inflating torso, pillowy-soft but no less constricting for it. Likewise, the overfilled curves that had been her neck were on their way to engulfing Octavia’s face—bulging around her puffy cheeks and over her crown, pinning the pointy balloons of her ears against the top of her head. Octavia couldn’t move any part of herself anymore. And it felt better than she ever could have imagined: she was embraced on every side by the softest, most luxurious cushion in the world, and simultaneously she was that cushion.

In spite of her glorious immobility, Octavia’s bloating body was far from still—wobbling and shaking beyond her control as she continued to inflate. Part of this was residual jiggling from her last futile attempt to move her legs, but a larger part was the front door jostling her overfilled haunch as the would-be visitor continued trying to open it. With the force of Octavia’s inflated backside pushing against it, the door could barely crack half an inch, but even that slight degree of freedom was enough to squish into her backside and set her whole body wiggling delightfully.

The significance of her inflated rump pinning the door shut wasn’t lost on Octavia. Just as she grew more and more trapped within her body—sinking deeper into her own inflation with every passing moment—she also grew more trapped within the room by the second, spreading further across all four walls, filling more space with her own relentless expansion. Her rump cheeks covered the front door and windows; her belly’s side bulged through doorways at the back of the room leading to the kitchen and hallway. Octavia’s bloated body had blocked off every possible entrance to this room—and with it, had preempted the possibility of anypony stopping her inflation. Already too large and round to save herself from further inflation, she had reached the point where no one else could help her, either—and still, she was expanding even further.

Thoughts of Octavia’s impending room-filling fate raced through her mind, as her head sank deeper into her torso, her ears disappearing completely beneath the inflated collar that had been her neck. “Mmmmmhhhhh…” she moaned into the helium nozzle, her contented voice echoing through puffy cheeks, each nearly thrice the size of her head. Above, the curves of her back were wide enough, they could have served as a dance floor for Vinyl’s party—and her rump large enough, each cheek could have been a buffet table—that is, if they weren’t pressing against the ceiling, squishing between the rafters. On her overfilled torso’s sides, the bloated doughnut shapes of her shoulders and haunches were twice Octavia’s normal height. And that torso was her largest feature, and still expanding even larger, filling with fifty, then sixty times her normal volume in helium, courtesy of the two tanks still pumping gas into her from both ends.

———

Outside, Lupin tried pushing the door one last time, but still had no luck. “Well, that’s no good,” he said. “I don’t—”

“Sshhhh!” Radicchio interrupted. “Everypony be quiet! She’s coming!”

Eyes widened and everyone fell silent. Then they distinctly heard hoofsteps approaching, and the voice of Vinyl Scratch humming to herself.

“What do we do? What do we do?” Radicchio whispered, prancing nervously in place.

“Hide!” Minty whispered as loudly as he dared. “Everyone hide in the bushes!”

But a quick glance around confirmed there was only one bush: a tall, skinny shrub trimmed into a musical note (whose exact name was the subject of much debate between this house’s two residents: Vinyl called it an “eight note” while Octavia insisted it was a “quaver”). And that bush was right behind Radicchio. Before she could react, the twenty-six other ponies trampled over her, flattening the pegasus underhoof in their mad dash towards the bush. Those party guests leaped into it, disappearing into the branches and leaves with just a slight rustle.

A few seconds later, Radicchio pushed herself off the ground. She shook her hoof-flattened body, her head clanging like a cowbell, until she regained her third dimension with a quiet pop! Then she, too, jumped into the shrub—and bounced right off. The bush was now more crowded than a phone booth full of frat colts, and there wasn’t enough room left for a ladybug, let alone a pegasus mare.

Vinyl Scratch’s humming continued as she drew closer. Scant seconds remained for Radicchio to find a hiding spot before Vinyl got close enough to see her. Her heart pounding, she looked quickly around the front yard—and saw the mailbox. It was smaller than her own head. Without hesitating, Radicchio yanked open the door and jumped in. She pulled her hind hooves in, snapping the door shut behind her, just before Vinyl rounded the bend.

———

The smaller helium tank, the one that had started this whole mess, disappeared completely between Octavia’s enormous rump cheeks. Those puffy posterior balloons squeaked in triumph as they enveloped that cylinder to squish against each other, unimpeded.

On the other side of the room, Octavia’s head was drawing inexorably closer to that same fate—inch by inch, sinking deeper into the place where her neck blended into her inflating torso. That puffy collar had completely flattened her mane and swallowed the pointy balloons of her ears. It bulged around her inflated cheeks—more than three times as big as her head now—faster than they could grow. From a side view, only her snout still poked out from the gigantic orb of her expanding gray body. And from Octavia’s viewpoint, her snout—and the nozzle it was helplessly latched onto, still pumping countless cubic feet of gas down her throat—was all she could see anymore.

But with the increasing sensitivity as her body ballooned ever larger, Octavia felt everything that happened in the room, rendering vision almost redundant. She could sense the outline of every piece of furniture pinned to the wall by her bloating belly. She could count every rafter in the ceiling by touch and discern how deep the spaces were between them. She could feel her body squeezing further and further into the corners, threatening to fill every cubic inch of the room with her mass.

And of course, Octavia could distinguish individual party balloons in the bunch trapped between the wall and her puffy right shoulder. That she couldn’t see them with her eyes just made it easier to picture them in her mind as a herd of miniature, gray earth ponies. As the balloon-ponies jostled against each other and against Octavia, each movement reverberated through her inflated body; every rubbery laugh echoed inside her head.

“Hahaha! Bigger! Bigger!” they called out in their squeaky voices.

“Hhrrrmmmmmmmmm…” was all Octavia could say in response, as she gulped down yet more helium and sank another inch deeper into her own bloated body. The smaller helium tank, hidden in the crevice of her massive rump, finally ran out—but Octavia’s inflation continued only slightly slower than before. She couldn’t begin to guess how much gas remained in the larger tank, waiting to fill her even larger.

She spread out another foot—and then no further. Octavia completely filled the room, fully squishing into all eight corners. “Mmmmmm…” she moaned into the nozzle, as every square inch of the walls, floor, and ceiling pushed back against her, as did every piece of furniture her body enveloped. Notes of pleasure, far too many for Octavia to count, played across her impossibly stretched, impossibly sensitive skin.

Even though there was no more space to expand inside the room, the gas tank relentlessly pumped yet more helium into Octavia, building up the pressure inside her. She bulged a few feet out the doorways into the back of the house, and she could even feel the front door bending outward from the force of her continued inflation, but these weren’t enough. The air pressure inside Octavia was building up too quickly for those small openings to offer enough relief. Something had to give.

“Bigger!” one of the imaginary balloon-ponies squeaked. “Bigger, bigger, eeeeeEEEE—” With one last cry of complete ecstasy, she popped—overwhelmed by the pressure of Octavia’s continued expansion.

“Oooh, me next! MeeeEEEE—” Another balloon pony cried out in joy as she, too, exploded.

Octavia’s eyes widened at the sudden sharp sensation against the massive curve of her shoulder, and then the brief moment of relief as she expanded into the suddenly vacant space. She moaned once again, just as the puffy collar of her neck bulged all the way around her snout—trapping her entire head inside the enormous balloon of her body.

“Bigger, bigger!” the balloon-ponies continued to call, their squeaky voices echoing through Octavia’s gas-filled body even louder than before. “Pop us all! Do it!” Then a few more of them popped loudly, each accompanied by another ecstatic cry.

And Octavia couldn’t help but do as the balloons told her. She was discovering new frontiers of immobilization now: her head and limbs completely swallowed by her inflated torso, embraced by her own pillowy softness too tightly to move even an inch. And as the waves of pleasure overwhelmed her brain—a new burst of joy washing over her with every party balloon she popped—she could no longer think enough to even imagine the possibility of escape. All Octavia could do now was gulp down more and more helium, and break through anything trying to impede her continued expansion. She was going to pop every one of these party balloons, then break every piece of furniture in the room. And then, with just the walls of the house holding her back…

“WheeeEEEE—” Yet another balloon shouted joyfully as she popped.

Sinking a few inches deeper into her own body, Octavia moaned once again and swallowed another cubic foot of helium.

———

Vinyl Scratch hummed to herself as she cantered along the path to her front door. She pulled a cart with her magic, following a few feet behind her, bearing her birthday self-gift: brand-new state-of-the-art Ørwå Tëvër 3000 model subwoofer. She passed the eight-note shrub and the mailbox without even sparing a glance, and walked right up to the door.

Vinyl grabbed the doorknob with her magic—then paused, and let the song on her lips go silent. “Hmmm?” Something seemed off, but she couldn’t quite put her hoof on it. She shrugged and tried to open the door, only to find that it wouldn’t budge. The door wouldn’t even rattle in its frame; it felt like something was pushing against the other side, pinning the door shut more firmly than any lock.

Come to think of it, the door wasn’t supposed to bulge outward, was it? And those cracks in the door frame looked new…

Vinyl’s eyes widened behind her shades. She jumped out of the way—just before the door exploded off its hinges. It flew across the yard, ricocheted off the mailbox, and bounced straight up into the sky.

But Vinyl’s attention was instead on what was now visible through the exposed doorway. A fuzzy, mostly gray surface completely filled the doorway, bulging slightly through—in fact, it continued swelling further as Vinyl watched. In the upper corner, there was a patch of purple, in a shape that looked oddly familiar. Come to think of it, Vinyl was pretty sure she recognized those specific shades of gray and purple, too…

A noise from behind drew Vinyl’s attention back to the yard. The mailbox was still wobbling like a spring from its recent collision with the door. Suddenly it opened, and Radicchio tumbled out, sprawling on her belly in the grass. Then dozens of envelopes spilled out, enough to nearly bury the pegasus.

Vinyl raised her sunglasses and squinted.

“Um…” Radicchio said, shaking off the avalanche of mail. “Surprise?”

Then the shrub quaver quivered, and twenty-six more ponies stuck their heads out from the greenery. “Surprise!” they shouted in unison.“Happy birthday!”

A smile lit up Vinyl’s face as she replied, “Epic! All my friends are here! And Radicchio is here, too.” But as she scanned her birthday guests, her face fell as she realized… “Wait, where’s ’Tavi?”

“That’s what we were wondering,” Twintails replied, leaping out of the shrub. “She’s the one who organized this party, but we haven’t seen hide nor hair of her! I was hoping you knew where she was.”

Vinyl Scratch scrunched her nose. “Yeah, I’ve been scoping out new gear all day—” At this, she brushed a hoof gently across the new subwoofer at her side. “—and I haven’t seen ’Tavi since breakfast. So where is she now?” She spun back around to the door, noting how the fuzzy, gray-and-purple mass was now bulging even farther through the doorway, jutting several feet into the yard at the farthest point. “Really, your guess is as good as mine.”

Extending a foreleg, Vinyl prodded that huge, fuzzy curve tentatively, until her hoof sank completely into its pillowy softness with a few quiet squeaks. It felt… familiar, just like this specific combination of gray and purple looked familiar. “I don’t suppose anypony knows that this thing is either?” As Vinyl’s hoof squished deeper into the familiar surface, it pushed back—the pressure increasing by the second. This round, soft, strangely familiar object, whatever it might be, was definitely still growing. “Whatever it is, it’s awfully…”

Behind her shades, Vinyl’s eyes widened as she suddenly understood why this was so familiar. “Oh.”

“Oh, what?” Minty asked.

“Oh, just, uh…” Vinyl called back, suddenly thankful she was both facing away from her guests and wearing sunglasses. “Hey! Yanno, why don’t we see about getting inside first? I’m sure ’Tavi’ll show up eventually.” With a weak chuckle, Vinyl reared and spread her forelegs wide, then leaned forward to embrace as much of the round, gray surface as she could reach. Her whole torso squished into it a few inches; she pressed the side of her face against it until her sunglasses went crooked. “Just gotta try and get past this… thing… Probably just, yanno, something that ’Tavi bought that went off early, hehe.” She punctuated this by squeezing that surface harder, producing some more rubbery squeaks, trying to dislodge the trapped balloon of her roommate. Belonging to her roommate. “Man, what a day, huh?”

The mysterious gray thing’s continued growth forced her to take a step back. Sheesh, ’Tavi, Vinyl thought to herself. I can’t wait to hear you explain how this one happened.

Meanwhile, she rubbed her forelegs up and down against its sides, making it jiggle several more times. “First Tavi goes missing, then a gift of hers goes off while she’s gone. What a strange pair of…” She squeezed again, drawing one more squeak. “…completely…” Squeeze again, squeak again. “…unrelated…” Squeeze, squeak. “…events.”

“Yeah,” Radicchio said, finally standing up and emerging from the landslide of letters. “And on your birthday, of all days! What are the odds?”

Vinyl’s front door fell from the sky, directly onto Radicchio, squashing her flat for the second time.

“Yeah, totally,” Vinyl said, half-paying attention. She sank a few inches deeper as Octavia… ’s left-behind inflatable pressed back against her even harder. “What are the—huh?”

A few brittle snaps drew Vinyl’s attention back to the doorframe: the cracks around it were noticeably bigger than they’d been a few minutes ago. In fact, the house’s entire façade was bulging outward ominously, now. The gray balloon squeezed out the doorway another few inches, and new cracks appeared right under Vinyl’s gaze.

“Uh oh,” Vinyl Scratch said, as she stepped back. Silently thanking her lucky stars for those mandatory college credits in spellcasting, she closed her eyes and mentally visualized a standard teleportation matrix. Her horn flared, and a bright light briefly burst from the doors and windows.

When she opened her eyes again, the house was empty—and right next to it was a very full Octavia… -purchased gray balloon, her immense new size on full display. White and gold party streamers were draped across it, along with a banner reading:

♫ HAPPY BIRTHDAY VINYL SCRAT♫

A jumbo-sized helium tank was wedged into one end, even now continuing to inflate her even larger—but Vinyl was quick to yank it away, confidently enough that nopony thought to question it. She couldn’t help but notice a bunch of normal-sized party balloons tied to the helium tank, most of them already popped. Meanwhile, the pressure inside the massive balloon was enough to seal her mouth-valve shut, preventing her from deflating at all. Vinyl reached out with her magic and grabbed her balloon before she could drift away, only to realize that wasn’t quite necessary. Even filled this large, somehow, Octavia’s… balloon’s mass still slightly outweighed the helium’s buoyancy.

Well, ’Tavi, Vinyl thought, however you’re feeling now, I just hope it’s enough to distract you from all this. Can’t imagine how mortified you’ll be if it isn’t. Wait… is that you moaning?

No longer confined by walls, the gray balloon of a roommate… gray balloon belonging to her roommate was almost as tall as the house, and easily wider than it by a few dozen feet. Overall, she had adopted a squashed sphere in shape, but with some irregularities. There were five doughnut shapes arranged around the equator, with a deep divot in the center of each. And on one side, a pair of smaller balloons were attached—though they only looked small in comparison to the body’s ridiculous size, each of those cheek-like orbs individually larger than Vinyl’s bed. Emblazoned across both smaller balloons was a very familiar symbol…

Moment of truth, Vinyl thought. Here goes nothing.

“Do you see that, everypony?” Vinyl asked, plastering a grin across her face as she spun to face her guests. “Clear as a crisp spring morning! Octavia’s cutie mark… on the balloon! Just like I told you!”

All the party guests just stared back at her, confusion written across their faces. Radicchio lifted the door a few inches and said, “I don’t follow.”

Vinyl chuckled. “Obviously, ’Tavi wanted to arrange a totally epic birthday party for me… so she rented this giant inflatable for all of us to bounce on, duh! Of course, this means ’Tavi can't join us herself, because a serious bounce party is way more intense than her usual scene. But ’Tavi made sure to get a bounce pad with her cutie mark on it, so there’d be no mistaking who set all this up.”

The party guests murmured at that: “Oh, yeah. Makes sense.”

“Seems pretty reasonable to me.”

“I literally can’t think of a more plausible explanation for these events.”

Vinyl loosed a long sigh as she thought, ’Tavi, I hope you can forgive me.

Looking back up, she silenced the crowd by clearing her throat. “Now, the fact ’Tavi knew she wouldn’t like this party, but organized it for me anyway, just goes to show what a good friend she is. Sooooooooo, let’s all give a round of applause for the mare who made all this happen!”

Cheers and hoof-stomps filled the air for nearly thirty seconds, until…

BWOOOOOMP! WUB WUB WUB…

The bass dropped so hard, it knocked almost everypony off their hooves. In the time it took for everyone to cheer, Vinyl had managed to get her brand-new subwoofer hooked up to the hi-fi, and was now blasting one of her favorite LPs, volume cranked up to eleven. Even from inside the house, the stereo system was more than loud enough for a party outside.

Vinyl herself had already clambered atop the gray inflatable’s massive form, prompting another familiar moaning sound to echo through the enormous sphere. That can’t be a coincidence, Vinyl thought, lifting an eyebrow behind her shades. She jumped once, tentatively, sinking into her overfilled roommate… ’s balloon—and she heard that sound again from beneath her hooves. With a smirk on her muzzle, Vinyl thought, Maybe Tavi’ll be more forgiving about this than I thought…

“C’mon everypony!” she shouted as she jumped, once more, then twice, bouncing higher than her own house with the oversized balloon’s help. “Let’s get this party started!”

———

An hour later…

Night had fallen, but the moonlight (helped by a few lanterns in the front yard) was bright enough that the birthday bash could continue unabated. Raucous music still played from the stereo inside. Some of the guests were on the ground, mingling amongst themselves, but over half of them were still bouncing and cavorting like oversized foals on the huge gray blimp in the front yard.

Vinyl Scratch was the only pony who had not taken a break from bouncing at any point. At this moment, she was focused on height. Already, she could bounce twice as high as her own house, clearing even the tops of all the nearby trees. By timing her jumps just right, every bounce took Vinyl a few inches higher than the last—and upon each landing, she sank a few inches deeper than before into her roommate’s balloon’s elastic squishiness. For the brief moment of weightlessness at the apex of each bounce, Vinyl could almost believe she really was floating among the stars. Then for the brief moment her hooves squeezed deep into the gray balloon before rebounding, she couldn’t help but hear those deep reverberations, sounding more and more like moans of pleasure…

“Happy Birthday, Vinyl Scratch!” A voice suddenly cut through Vinyl’s thoughts. Pinkie Pie had arrived at some point, and was now bouncing alongside her. “How’s your party going?”

“Huh?”

“You know,” Pinkie continued, “I saw Octavia earlier today, and she mentioned to me how much she wanted your party to be perfect! So did she do it? Did she make the wonderfullest, most fantabulously splendoriffic party you’ve ever been to?” Pinkie paused to glance around. Her curly mane flapped in the air as she soared up and down at Vinyl’s side. “And where is Octavia, anyway?”

“Well… to answer both your questions…” Vinyl continued to bounce as she replied. “…Octavia set me up a party so awesome that she couldn’t handle it herself and had to skip! Gotta admit, I was expecting her to arrange a shindig for total squares—like something with healthy snacks, mentally stimulating board games, and traditional folk music from every corner of Equestria. Can you imagine how lame that woulda been? But this—a huge bouncy balloon, filled to a perfect mix of soft and tight for comfiness and bounce height? This is epic!”

Pinkie could only squeeeee in response to that. Then after a few more jumps, she added, “Hey… is it just me, or is the balloon making funny noises every time we bounce on it?”

“Oh, uh, y-yeah.” Vinyl had enough time to shrug in midair, letting out a weak chuckle. “That’s probably just the latex or rubber or whatever squeaking. You know how inflatables can be.”

“I don’t think it sounds like any inflatable I’ve ever heard. Almost sounds more like—”

“Just. Latex. Squeaking.” Vinyl lowered her sunglasses just enough to glare over them at Pinkie. “Perfectly normal sounds for a perfectly normal giant balloon, that just coincidentally happens to be colored like my best friend.”

“Alright, if you say so.” Now it was Pinkie’s turn to shrug in midair. “But in my professional opinion, I think this balloon…” Pinkie reached into her mane and, impossibly, pulled out a metal cylinder—a compressed air tank. “…is a little underinflated. You mind if I give it a boost?”

Vinyl’s eyes opened wide at the fresh tank, before looking down to the gray immensity below her hooves as she bounced off once more—prompting another of those mysterious moans. She looked back to Pinkie, a knowing grin on her muzzle. “Totally! The, uh, valve’s right over there.”

Humming to herself, Pinkie bounced over to the indicated spot: one of the doughnut shapes on the massive balloon’s side. She shoved the air tank, nozzle-first, deep into the divot, and the valve opened with a muffled hiss. The effect was immediate—Octavia’s gray balloon rapidly expanded another inch, two inches, and then kept going.

“Woohoo!” Vinyl called, bouncing even higher than before. Underneath, the bouncy blimp inflated even taller than their house, and just kept growing—allowing Vinyl to rebound off her to ever higher heights. Octavia’s balloon wobbled wildly, shaking as Vinyl bounced relentlessly atop her, along with over a dozen guests, all of them none the wiser.

And among all that, there was a sound—almost completely drowned out by the whoops and hollers of the party guests, by the squeaks and creaks of Octavia’s balloon’s surface expanding, and by the hiss of Pinkie’s air tank pumping even more gallons of gas into her. Beneath all those other noises, Vinyl could hear it clear as day every time she landed and squished inches deep into the huge gray blimp before rebounding. Echoing deep within that massively overfilled form, mixing with the squeaks and creaks, were noises that really did sound almost exactly like repeated moans of pleasure.

“Yeah, fill ’er up, Pinkie!” Vinyl shouted. “I’m gonna bounce this baby all the way to the mooooooooon!”

———

Author's Note

Twintails belongs to thefurryrailfan; Minty Candy belongs to MintyCandy; Lupin Quill belongs to Lupin Quill; Linework belongs to wydzard.

Radicchio is my OC ~~(do not steal)~~ (actually go ahead and steal, as long as you fill her up at least twice as big as before).