Twilight sat up in her bed, covered in blankets and completely miserable.
"Uggghhhh."
A line of mucus hung out of her left nostril. One quick snort later, it pulled back in, disappearing into her nose.
"I knew I had been pushing it with all this late night studying, but I didn't think I was headed for a sinus infection."
The door to Twilight's room slammed open. Spike wandered in, carrying a tray with a piping hot cup of tea resting upon it.
"Who said you've been staying up too late?"
Twilight rolled her eyes. "You did, Spike."
"And who said you needed to take a day off?"
"That would be you again, my faithful assistant. Achoo!"
The baby dragon placed the cup on Twilight's bedside table and shook his head. "Maybe next time you'll listen to me."
A purple glow engulfed the cup and brought it to her lips. "Thanks for the tea, Spike. With you around, I know I won't be sick long."
Taking a delicate sip of the tea, she felt it rush through her body, warming her to her very core. "I Just feel awful. Even my stomach feels bloated," Twilight whined, placing a hoof across her sore belly.
Spike put the platter on his head, balancing it to amuse himself. "Well, don't you worry about anything. I've got it all handled. That reminds me, I need to go let Fluttershy know you won't be able to make it."
Twilight's eyes went wide and she spit out a spray of tea.
"Oh my gosh! I was supposed to help Fluttershy move those rocks out of her pond! I've gotta go help her!"
Tossing her blanket aside, Twilight hit the floor, her hooves barely able to hold her weight. She took a few steps to the window before Spike jumped in front of her.
"No way! You're not going anywhere!"
"Spike," Twilight began. "Fluttershy can't move those boulders all on her own, and if we don't get them out, the fish might die! I have to help her!"
Spike extended his arms as much as he could... which is to say, not much. "No, Twilight, not this time."
Flapping her wings, Twilight flew over Spike's head and out the window. "Sorry, Spike. I'll be back soon to rest, I promise!"
Soaring high above Ponyville, the sun beamed down on her. It wasn't very warm outside, it being so close to winter and all, but the sun felt good on her back regardless. What didn't feel good was the sudden bout of queasiness.
"Bleh. I might need to find a place to land."
Having passed over Ponyville, she found herself above the field between the town and Fluttershy's cottage. Luckily there were a few clouds about. Spying one about fifty feet above her, she flapped harder, soaring higher into the sky.
She landed on the cloud with a soft whumph and sighed. "Maybe this wasn't such a good idea."
Rolling over on her back, Twilight gasped in shock.
"My stomach! It's gotten bigger!"
In her bed it had merely puffed out a little beneath her sheets. Now it bulged outward like she had swallowed a basketball.
"I hope nopony sees me up here like this..."
Looking around, Twilight spotted another cloud higher up. A larger, perhaps fluffier one to lay her sore tummy. One that promised a little bit more privacy. Once more she took flight and climbed higher. As her wings flapped, she felt gravity fight harder and harder against her. Moments later, she plopped down on the cloud and sighed.
"Whew... WAAAAAAAAAAA!"
The scream trailed off as the alicorn took stock of her stomach. It had grown much further, now about three feet in diameter. She groped it, trying to force the air out.
"What's wrong with me?!" she wailed, her hooves trying to reach across the wide expanse of her swollen stomach.
"Hehehehehe. Well look who it is."
Twilight knew that scratchy voice anywhere. "Rainbow Dash! It's not funny! Where are you?"
"I'm up here, egghead!"
Glancing up, Twilight scowled at the pegasus hovering over her. "Rainbow, I need you to go to the library and look up any illnesses that present with sinus infection symptoms and abdominal swelling."
Rainbow Dash touched down on the cloud and blew a stray lock of hair out of her face. "I don't need to. I already know what's wrong."
"You... do?" Twilight asked.
"Yup! Remember when you found me on a cloud at Sweet Apple Acres and I was-"
Twilight stuck out her tongue in distaste. “-Passing gas, yes, I remember. And then you told me you'd teach me how. Disgusting."
Rainbow snickered. "Well, egghead, if you had bothered to read a book about pegasi, you'd know we have to toot our horn regularly. If we don't, the air that keeps us afloat gets stale and we get an infection."
"Wait... you mean... you HAVE to pass gas like that?" Twilight asked.
"Yup," Rainbow said with a nod. "If you don't, you get an infection and anytime you fly while infected, you get larger and larger until you're nothing but a big old balloon. Of course... some pegasi like it... some pegasi like me," Rainbow said, placing a hoof on Twilight's swollen belly. Twilight swatted her hoof away.
"Wait, you mean some pegasi enjoy this? You're crazy!"
Rainbow snickered. "Then I guess you're crazy too." Rainbow placed her hoof back on Twilight's belly and started gently massaging it. A passionate moan escaped Twilight's lips, soon followed by a crimson blush.
"Ra-Rainbow... what are you doing?" She asked.
The pegasus placed both of her front hooves on Twilight's bloated form and began squeezing and prodding. "I'm making you feel good, egghead. See. There's two ways you can get better. One, you sit inside, drink lots of fluids, stay warm, and at some point your body purifies the air."
"An-and the other?"
Rainbow reached down to Twilight's marehood and gently rubbed her hoof along the alicorn's engorged lips. Twilight was practically soaking the cloud with her arousal, enough for Rainbow to pull back a hoof covered in wetness.
"The other way... the fun way... we take you higher and higher and play around. Eventually you'll get so big that you pop sorta... and all the bad air escapes."
Twilight frowned. "That's so unseemly. I mean, what if somepony sees us. Not to mention I'd be... ya know... with you."
Looking away with grunt, Rainbow walked to the edge of the cloud. "Oh I get it. That's cool. I'm sure I have some clouds around here that need busting. I'll catch you later Twi. Not like you're going anywhere."
Looking down at her belly, Twilight saw that it had indeed grown further, forcing her legs apart. Try as she might, she couldn't roll over to stand up. Just as Rainbow spread her wings, Twilight raised her hoof.
"Rainbow, wait!"
The blue mare turned, a sly grin plastered on her face. "What? Do you need something?"
Putting on her best pouty face Twilight nodded. "Yes. Can you help me? Please?"
Rainbow cackled and walked back to Twilight's side. "Sure I can. What kind of friend would I be if I wasn't loyal?"
"So, what do we do," Twilight asked with pleading eyes. Rainbow grabbed the alicorn by her swollen belly and flapped her wings.
"All you have to do is hold on. I'll take care of the rest."
Twilight's stomach lurched as Rainbow grabbed her front legs and zoomed off higher into the sky. Suddenly, a feeling of pressure washed over the alicorn. She wasn't sure if it was fogginess clouding her mind thanks to the illness, or Rainbow's propensity for speed, but she soon lost track of how high they were. As they climbed, however, Twilight's midsection started rounding out more and more. Her hooves were forced up by the rounding of her stomach, and the arousal between her legs only grew.
"Rai-Rainbow... are we almost there?" Twilight asked.
"Yup. Just hang on a bit longer."
Higher the couple climbed into the sky, the air around them cooling off. Wider and rounder Twilight grew, her belly starting to encompass her entire body. An audible hiss could be heard just above the rushing wind as Rainbow finally picked a cloud to stop on. With a playful toss, Twilight's bloated body hit the cloud, causing a wisp of cloud to fly up.
"Here we are, and you're coming along nicely."
"Rainbow, have you gotten smaller? I feel like you're not as tall as you used to be?"
Rainbow cackled and prodded Twilight's swollen barrel. "Nope. I'm still the same cool size. You though, you're huge! Many pegasi would have popped by now. I wonder if it's because you're an alicorn..."
Twilight grunted in frustration. Her leaking marehood needed attention and the pressure grew as she kept getting bigger and bigger. Her body was now nearly encompassed by her bloated belly, completely stranding her on the cloud. Her hooves stuck out at absurd angles, uselessly flapping as much as they could. Her tail had nearly been swallowed up completely, unable to move at all. All told, she was more than double Rainbow's height, and simply wanted to get off so she could be done with this experience. Still, the curiosity won out.
"You mean, you don't usually get this big?"
Rainbow cackled. "I do, but not many pegasi do. Gotta say, you're doing pretty good for your first time."
At this moment, Twilight's cheeks started to bulge with excess air. "Gee thanks... but is there any way we can get this going?"
"Yeah, yeah. When your mouth goes all poofy like that, it means you're close. All I gotta do is stir the pot."
Rainbow took flight and zoomed around to Twilight's bloated backside. There under her massive and buttcheeks with four foot wide cutie marks, she spotted her prize. Twilight's pussy lips had swollen with excess air, becoming fat and puffy. A steady stream of nectar oozed between them, leaking into the cloud.
"Oh yeah... I'm gonna enjoy this for sure," Rainbow moaned, rubbing her slick marehood with her hoof. Bending over, Rainbow licked the alicorn’s swollen pussy lips. The effect was instant. A gasp escaped Twilight’s lips as her ballooned midsection wobbled with sudden growth. An angry hissing started deep inside the blimped alicorn as she bloated outwards with another two inches of growth.
Smiling broadly, Rainbow rolled Twilight like a giant ball until her marehood stuck out. Slowly those puffy lips grew larger as nectar dribbled out between them.
“Here we go, balloon butt. Hold it together as long as you can.”
Rainbow lowered her own dripping snatch ontop of Twilight’s. She rubbed her hips against Twilight’s ballooning side, grinding their marehoods together.
“Hah! Rainbow! Don’t stop!”
“Ngghah! I don’t plan to!”
The rubbing intensified as did the growth. It was only a few more minutes before Rainbow had to back up as they ran out of room on the cloud. Frustrated, Rainbow spun Twilight around until her marehood was facing up toward the sky. Quickly she flew up on top of Twilight and planted her pussy on top of Twilight’s needy lips.
“Oh yes, oh yes, get bigger for me!”
The pressure mounted inside the alicorn. Her cheeks bulged with air, a steady stream pushing through her lips. Still she grew wider, a purple 20 foot blimp in the sky. With each thrust, Twilight’s skin creaked and stretched more and more as inch after inch she swelled outward. Rainbow kept grinding her pussy against Twilight’s, anxious to get off before Twilight popped.
“Come on, come on, pant, uuuurghaaah!”
Marecum sprayed from Rainbow’s cunt all over Twilight, sending a stream of her femcum dripping down her ballooned side. All at once, the hissing inside the alicorn intensified. Her belly nearly exploded outward, gaining several inches at once as the hiss echoed inside her. muffled moans escaped Twilight’s lips as she pushed outward in all directions, raising Rainbow and her domelike belly further into the sky. The squeaking intensified until finally a spray of liquid shot out of Twilight’s snatch, spraying outward and soaking both her and the pegasus panting ontop of her. A loud bassy boom echoed in the clear open sky.
Falling into the cloud, Rainbow and Twilight panted and struggled for air. Twilight was back to her normal, svelte shape, but dripping with fluid. “That was… intense!”
Rainbow slowly sat up. “Sure was. You’re the best one I’ve ever seen! So, what do you think?”
Shaking the fogginess out of her head, Twilight slowly rose to her hooves with a dumb smile on her face. “I think that beats spending a couple days under a blanket. Thanks, Rainbow Dash.”
The rainbow maned pegasus flapped her wings a few times, rising into the sky. “You know what they say, A friend in need is a friend indeed. Catch you later, Twi!”
Twilight watched as Rainbow took off. Despite having just rid herself of the stale air, Twilight wondered if there was some way to make it happen sooner, or to get even bigger.
“That can wait till later. Fluttershy needs my help!”
Twilight took off toward the humble cottage Fluttershy called home with a new smile upon her face and a bit of extra speed behind her.
