An Expansive Demonstration

by Kifstopher

Rating: mature
Tags: Equestria Girls, Sex, Princess Celestia, Slice of Life, Sweetie Belle, Apple Bloom
Length: 3985

Apple Bloom demonstrates her new growth serum at the science fair by having Sweetie Belle as her test subject. Things get out of hand.

The Canterlot High Science Fair is here, and this year, Apple Bloom has got something that is sure to please the crowds: Her brand new growth serum! However, she needs a test subject for her demonstration, and so she employs her best (and shortest!) friend, Sweetie Belle, with the hopes of making her tall enough to impress the judges.

The only problem is that Apple Bloom isn't entirely sure if she's got it working right...

Contains: Growth, breast expansion, macro, destruction.

(Note: All characters are over 18 years old.)

Published 2015-11-11 22:30:02 UTC
Last updated 2015-11-11 22:30:02 UTC

A Positive Reaction

Sweetie Belle looked in the mirror, adjusting herself on the little stool, unable to get the cushion just right underneath her yellow skirt. She sighed, picking up a brush off the vanity and running it through her hair for roughly the three-thousandth time. The backstage room she was in echoed with the noise of the crowd in the auditorium, all the students gathered to watch their colleagues demonstrate what their experiments were. "Hm..." she murmured, putting the brush down again.

"Feelin' a li'l nervous?" her friend, Apple Bloom said, coming up behind her and placing her hand on her shoulder.

Sweetie gave a weak smile. "A little," she said, putting one hand over the other.

"Hey, don't worry 'bout it," Apple Bloom said, giving her a light pat, "Ah've tested it dozens'a times and not once did somethin' go wrong."

"I know, you've told me that already," she replied, "It's just that I'm not too good with crowds, and I've been feeling a bit meh today anyway." Gingerly, she rubbed her lap, looking down a bit.

Apple Bloom was about to say something, but from behind them, the voice of Cheerilee called out, "Apple Bloom, you're up!"

"Be there in a second!" she called back, waving at the person in the door. Then, she pulled on Sweetie Belle's shoulder a little. "Come on, we're up!" she smiled reassuringly, "You'll do fine, trust me!"

Sweetie didn't look so sure, but she put on a small smile and stood up, adjusted her jacket and skirt, then slowly followed her friend towards the stage.

"Up next is Apple Bloom, and her assistant, Sweetie Belle!" Cheerilee announced into the microphone with a bright grin. The two young ladies walked out onto the stage to a rupturous applause of the few students in the audience who were paying attention, as well as Principal Celestia and Vice Principal Luna, who were sitting front and center.

Apple Bloom waved to the audience, proudly showing off a big smile as she walked towards the table holding her experiment. Sweetie Belle, however, quietly meandered out from behind the curtains, onto the stage, blushing and trying to not look at them directly.

"Howdy folks!" Apple Bloom said, grabbing the mic off the stand excitedly, "Ah've got somethin' real neat that y'all're gonna love!" She waited for an applause, but was instead met with the loud indifference of the student body conversing amongst themselves, as well as some unimpressed looks from the principal. "Ahem," she said, blushing and pulling on the collar of her shirt a bit, "Well, uh, lemme go get it and Ah'll show ya!" She put the mic back on the stand and went over to the table.

Sweetie Belle looked around in the crowd, relaxing a bit as she saw that most of her classmates weren't paying too much attention. She was especially thankful that Rarity wasn't there, because she was fairly certain that she would crumble under her sister's judging gaze.

"And here it is!" Apple Bloom yelled, pulling up a test tube full of a mysterious dark green liquid and holding it up for the crowd to see. She quickly walked back to the microphone, and said, "This right here is mah amazin' new growth serum!"

The crowd slowly began to pay a little more attention.

Apple Bloom smiled wryly, knowing she was sure to hook them with this. "And here tah demonstrate mah growth serum is mah lovely assistant, Sweetie Belle!" she said, pointing to her and holding the test tube out to her. When Sweetie didn't move for a few seconds, Apple Bloom quietly whispered, "Sweetie, take the serum!"

Sweetie Belle blinked and quickly came up to her friend, meekly taking the vial out of her hand. She looked at it, and was a little sickened by its color and seemingly snotty thickness, but Apple Bloom was giving her a little impatient hand signal, and a slight glare. Nervously, she brought the vial up against her lips, and leaned back, letting the goopy substance slide down her throat. When it was all out of the glass, she swallowed, and gave a shiver, not appreciating the taste nor texture.

The crowd seemed much more interested now, which greatly pleased Apple Bloom. "And in just a few moments, mah darlin' assistant Sweetie Belle will go from bein' just a measly five feet tall to six!"

Sweetie Belle raised her eyebrow at her friend, being a little insulted that she called her height 'measly,' but she shook it off. Her body was beginning to get all tingly, like when her arm falls asleep, but she could still move around and feel the air around her. Then, she looked up and noticed everyone in the room was watching her expectantly. Her face went a little red, and she grabbed one arm with the other, and looked towards the floor of the stage.

Then she blinked. The floor was slowly moving away from her, inching downwards at a steady rate. "W-wow, it's actually working..." she thought, looking wide-eyed at the floorboards. Suddenly, she noticed Apple Bloom standing next to her.

"As y'all can see, Sweetie Belle's growin' bigger!" she said, leaning right up against her so people could see the difference. "And in just a few more seconds, she'll be six feet tall!"

Sweetie Belle felt pleasantly surprised. Everybody in the crowd was watching her, even Principal Celestia, who seemed rather impressed, but she felt a little more confident knowing they weren't judging her. Soon enough, she reached six feet tall, which meant that she was now a full two inches above Apple Bloom's height. She sighed with relief, knowing that it would soon be over anyway.

Then Sweetie kept growing.

The crowd watched as she continued inching upwards, slowly becoming even taller than her friend. Apple Bloom's wide smile faltered a little, but she kept it up, despite what was happening.

Principal Celestia was not as enthused. "Uh, Apple Bloom, you said she'd grow to six feet then stop, right?" she asked, raising an eyebrow.

"Did Ah?" Apple Bloom said, scratching the back of her head and blushing. "Well, uh, Ah meant to say, uh...Seven feet!" she said, raising her arms excitedly.

Sweetie Belle frowned, leaning down to her now six-inches-shorter friend. "Apple Bloom, what's going on?" she whispered into her ear.

"Just hang on for a sec, Ah'm sure it'll stop any time now," she whispered back, then pulled another pose.

Sweetie Belle leaned back up and blushed. She was now six-foot-eight and already she was taller than almost all of the other students at the school, and the growing wasn't showing any signs of slowing down either. After a few more uncomfortable seconds of being stared at by everyone, she finally reached seven feet.

Then grew right past it.

Apple Bloom clenched her teeth with worry, and turned to face Celestia, who was whispering to her. "Apple Bloom, is everything going alright with your experiment?" she asked, "Do you need to go get something?"

"No, no!" Apple Bloom replied quickly, giving a weak wave, "Everythin's goin' jus' fine, trust me!" She turned to face Sweetie Belle, now having to look up to her. "Jus' stay calm," she murmured to her, then noticed something, "H-hang on a sec..." She looked closer at Sweetie's chest, which was difficult, considering Sweetie was now seven-foot-six. Very, very quietly, she asked, "...Are your boobs growin', too?"

Sweetie Belle's eyes widened, and she looked down at her chest. Indeed, her breasts did seem to be swelling up slowly, as they were much larger than her usual B-cups, her shirt having lifted up to reveal her navel. From underneath her shirt, she noticed two perky nipples peeking out from behind the fabric. Then she quickly looked back up after remembering the crowd in the room. Everyone was staring at her, talking fairly audibly amongst themselves about her.

"You think she's gonna keep growing like that?"

"What if she doesn't stop?"

"Am I the only one with a boner right now?"

Sweetie Belle passed eight feet in height, her face staying red. "I, erm..." she mumbled to herself, shuffling around in place as she tried to remain calm. Suddenly, there was a rather loud 'skrit' noise, and she looked back down. A tear had formed down the center of her shirt, revealing the marvelous cleavage of her now E-cup sized breasts, her nipples standing very pointedly under her shirt on either sides of the rip. "Eep!" she cried, quickly wrapping her chest in her arms.

"Riiip!"

She blushed, remembering that she had been wearing her jacket, which was now completely torn in half, the sleeves ripping from her increased arm size. Dejected, it fell to the floor of the stage, landing behind her as a yellow pile of tattered remains. Nervously, she pulled her arms tighter around her swelling chest as she passed nine-foot-six. "A-Apple Bloom?" she whispered, looking down to her friend.

Apple Bloom wasn't taking this situation well. She was busying herself by twiddling her thumbs, sweat dripping down her forehead. "Eh, eheh..." She chuckled awkwardly, blushing.

"I think I've seen enough," Principal Celestia stated, suddenly. "Apple Bloom, fix Sweetie Belle, now."

Apple Bloom tried to avoid her gaze for a minute, looking away from both Celestia and Sweetie Belle, who coincidentally had just passed ten feet tall. "Well, ah..." she mumbled, putting her hands behind her back, "The, uh...um..." She went quiet, feeling the intense glare of the principal on her neck. "Well, uh...Ah, uh...can't..."

"What do you mean 'can't?'" Celestia asked, raising an eyebrow. "Surely you thought that something like this might happen. Give Sweetie Belle the antidote, or whatever it is you have."

"See, uh, that's the thing here..." Apple Bloom squeaked, her face incredibly red, "...Ah didn't make one..."

"What?!" Celestia yelled, standing up.

Then, suddenly, "Riiiiip!" "Eeeeep!"

Everyone in the room turned to face Sweetie Belle, who had just screamed at the top of her lungs. In a small pile around her feet were a detroyed pair of pink boots, as well as a completely torn shirt and absolutely ruined pair of panties, topped off with a bra with snapped straps. She was slightly bent over, panting. She had one arm reaching down, trying to cover up her extremeties, and the other arm trying, and mostly failing, to cover up her now monstrous breasts. She was rapidly approaching twelve feet in height.

"Whoa!" Apple Bloom yelped, almost jumping backwards when she saw her giant friend. Sweetie Belle towered over her, she was barely able to reach up to her waist. "Ah mean, uh, um...Y-you're doin' great, Sweetie!"

Sweetie wasn't so sure. From the looks of things, the crowd of students was getting pretty riled up at her newfound nudity. Most discomforting were the several flashes of light, which she quickly realized were people's phones taking pictures of her. "Um-er..." She panted, her panic getting worse as she hit thirteen feet tall. Suddenly, she felt something bump against her head. Leaning down and looking up, she realized she had hit the top of the stage, and had an idea. She pulled her arm back, letting her now almost-person-sized breasts flop free for a few seconds, and grabbed the dark-violet curtain, giving it a strong yank.

The curtain didn't rip off like she hoped it would, but instead, the entire bar holding the curtain, as well as some sizeable chunks of wall that it was attatched to, came right off, crashing onto the floor. Regardless, she quickly pulled the curtain free from the bar and wrapped it around herself like a big towel.

"Phew..." Sweetie sighed, holding the curtain with one arm. Then, she looked back at the audience, which had gone completely quiet. Her eyes narrowed as she found herself blushing again. "S-sorry about that..." she squeaked to the principal.

Celestia was almost in shock. Sweetie Belle was now three times her normal size, and her boobs had ballooned up incredibly. She turned to Luna and whispered, "If we don't do something soon, she'll outgrow the whole auditorium!"

Luna nodded in agreement, and stood up next to her sister.

Celestia took the microphone off the stand, shooting a brief glare at Apple Bloom, then turned to face the students. "Attention, students," she said, raising her arm.

No one in the crowd acknowledged her, as they continued gawking at and snapping photos of Sweetie Belle.

"Attention, students!" Celestia said again, with more gusto.

Still, everyone kept watching Sweetie.

Luna leaned towards the microphone and yelled, "Listen up, everyone!"

That worked.

Celestia pulled the mic back and continued. "Everyone, I want to you all get into organized lines, and please exit the auditorium."

"Is Sweetie Belle gonna be alright?" someone in the audience called out.

"Vice Principal Luna and I will sort this matter out, in the meantime-"

There was suddenly a loud groaning noise coming from the stage, and all the students and faculty turned to look. Sweetie Belle was leaning further down, having passed eighteen feet in height, and becoming more and more panicked by the second. Below her feet, she noticed the floor of the stage dipping down, the floorboards creaking and groaning under her increasing weight. She turned to Apple Bloom, who just made a disheartening frown and shrugged.

Celestia turned back to the crowd. "In the meantime, I would like you all to wait outside, in the hall, quietly, while we work to help Apple Bloom sort this issue out. Now, everone in the back, please-"

With a loud "Crack!" and "Snap!" the bottom of the stage collapsed into a heap, knocking Apple Bloom onto her back while Sweetie Belle screamed, waving her arms around in the air.

The students at the front, as well as Vice Principal Luna, began to scream and run away, while Principal Celestia just stood there and turned slowly as a massive shadow suddenly surrounded her. Her eyes widened, and she gave a loud shout before she was abruptly bowled over by Sweetie Belle's massive breasts as the giant girl toppled over onto her.

Sweetie Belle screeched, her upper body and arms quickly demolishing several chairs below her as she flattened them. She panted for a moment, trying to move her arms without crushing anything else, though the effort was in vain, as even more rows of chairs were destroyed in the process. Most worryingly, she felt Celestia flailing between her breasts, pushing and grabbing them as she tried to escape. Sweetie blushed as she made an uncomfortable realization.

She was feeling just a little bit horny.

She laid there for a moment, feeling the Principal squirm between her growing mammaries, and she slowly put an arm around her chest as she tried to pull her out. As she reached closer, her hand sank between her massive breasts, and she accidentally squeezed down entirely on her own sensitive flesh. It was almost a burst of electricity. It felt amazing. Her whole body tingled at the intense warmth running through her body from that one simple squeeze.

"Mmm..." Sweetie Belle moaned, very loudly. For a brief moment, she heard a slight tearing noise, but she paid no attention to it as she busily rubbed her titty with her hand. Her eyes were half opened, her cheeks flushed with red as she groped herself in the middle of the room. Her ears buzzed for a few seconds, until it went quiet. She blinked a few times and looked at the doors.

Every student in the room was staring at her, wide-eyed and with several male students not even bothering trying to hide their erections.

Heat ran up her neck as she slowly leaned up, but she soon stopped when she felt her back rub up against the ceiling. She had grown to thirty feet very quickly, and her breasts were now both bigger than her head, nearly touching the floor despite her attempts to lean up.

Below her, Celestia seemed taken quite aback at Sweetie’s sudden outburst, but there was no time to think about it. She dashed to her feet and took off running towards the back, with the students.

Sweetie panted, she still felt very warm inside, a wet spot very visibly appearing between her legs. Her mind was fuzzy as she tried to think of what to do, but her mind kept slipping back to how absolutely wonderful it felt when she squeezed herself.

Apple Bloom scrambled to her feet and made a mad dash out the back door from behind the ruins of the stage, looking back and gulping as she saw her friend’s back begin to push up against the ceiling of the auditorium.

“S-Sweetie?” Principal Celestia said, nervously, “A-are you a-alright?”

Sweetie Belle’s thoughts were cloudy, her face flushing red as she kept thinking of groping herself, especially now considering there was even more to squeeze. She looked out to the students, hoping she could ward them off, but ended up wondering, "M-maybe...Maybe I could put a few between my titties...And squeeze them together..." The thought was very appealing, feeling all those tiny people squirming around between her luscious breasts, their little bodies wiggling around, groping and tickling her.

She resisted the urge to grab them, though now her breasts had grown so big, they were crushing more rows of chairs in the auditorium as they grew. Her nipples were bigger than a normal person’s head at this point, and were feeling pretty rock solid. Sweetie Belle’s back was pushing and pushing against the ceiling, cracks appearing as she reached thirty-seven feet tall. Bits of rubble and debris rained down in the room, tickling her sensitive flesh as they fell. with small beams of light shining through as it slowly gave way.

Soon, Sweetie almost couldn't stand it anymore, between the wetness between her legs and her growing mammaries, and she thought for just a second, “J-just one...A l-little one...” Gingerly, she reached back towards her chest, putting one hand on each breast, and as she started to lightly squeeze them...

Sweetie Belle’s libido erupted.

The ceiling and roof burst open as she pushed through them in a matter of seconds, her massive body overshadowing the entire audience. She grew fast, quickly becoming forty feet tall, then forty-five, then fifty. She squeezed her breasts hard, her rapidly growing orbs squishing into her hands as she groped herself. “Oooh, ooooh!” she moaned, drool dripping out of her mouth and dripping onto her massive white breasts.

Students ran screaming out of the room, looking back as Sweetie Belle’s massive body soon filled the entire auditorium, the walls in the hall beginning to crack and crumble as she became bigger and bigger.

“Ooooh! Oh my goodness, oooh!” Sweetie screamed, her entire body on fire from the pleasure she was getting. At seventy-five feet, her giant legs and massive rear had completely demolished the stage, as well as half the auditorium. The front half was faring no better, as her titanic titties had crushed it, as well as a rapidly increasing portion of the school itself. She was now completely outside, her whole body in broad daylight. Not that she noticed of course, she was too busy groping herself and humping the ruins of the auditorium to notice.

She grew faster the hornier she got, quickly hitting eighty feet tall, then shooting up to ninety. Her legs were getting dangerously close to the buildings across the street, their rapidly increasing massive size needing more room. At a hundred feet tall, she dwarfed the school building, her incredible breasts now seventy feet big on their own. They were too big for her to even stand up at this point, but she didn’t care. Sweetie kept on thrusting her hips back and forth, her pussy dripping with wetness and her swelling mammaries jiggling from the intense groping she was giving them.

“Bigger, bigger!” she moaned loud enough for everyone in town to hear, passing one-hundred and twenty feet. Half the school had been crushed by her growing body, her huge hands crashing down and wiping out classroom after classroom as she wildly grabbed all over.

Everyone had evacuated the building, and was standing in a crowd, watching idly as Sweetie Belle made short work of demolishing the school. Her breasts had become so massive, she could only lay down on top of them and grope wildly as she could, her growth increasing every second. Every grab was like a jolt of pleasure.

She kept growing and growing, one-hundred and fifty feet, one-hundred and seventy-five feet, two hundred feet tall! The whole school was gone, completely demolished underneath her gargantuan form. Where there had once been the auditorium, there was only a massive crater, filling with juices from her vagina and constantly crumbling deeper as she rammed her hips against it harder and harder. It was absolutely unbelievable the amount of pleasure she was feeling. The ground shook with the ferocity of her humping, which only increased as she thrust harder and faster. She groped and grabbed and squeezed her breasts, until finally...

Sweetie Belle came.

Almost like a tidal wave, her liquids splattered between her legs, sending a goopy mess down to the ground, covering most of the remains of the auditorium, even reaching the poor defenseless ruins of the building across the street, as well as the confused folks who had been inside. Her face flushed with red, her eyes screwing up as she let out a monstrous roar, echoing for miles. She had a massive surge in size, growing several feet per second as she came. It was the greatest thing she had ever felt in her entire life, zooming up past three-hundred feet and rapidly approaching four-hundred. Her breasts ballooned even bigger, swelling up dozens of feet at a time with every electrifying wave of pleasure.

People all around scrambled away, screaming and running for their lives as Sweetie Belle’s growing body practically bulldozed the area around her.

Slowly, though, she began to ease off with her humping, the pleasure and excitement of growing wearing off. She laid her head down on top of her massive breasts, resting on top of them as if they were a humongous pair of pillows, soft and fluffy, as her arms tiredly flopped over towards her cleavage.

Then, she peered downwards and noticed the crowd of tiny people gathered around her, with Principal Celestia and Vice Principal Luna at the front with barely visible looks of complete shock. Everyone was quiet, in complete awe of the magnificent giantess before them. She was huge, nearly five-hundred feet tall, with breasts that were nearly as big as she was, and easily dwarfed all the nearby buildings with her size, most of which had been flattened in her fervor.

Sweetie Belle blushed, looking at the crowd.

“Heheh...S-sorry...”

Apple Bloom blinked, not moving from her hiding position. Was it safe? She leaned up and took a look around. Surrounding her on both sides were massive walls of white, and in front of her, a huge vagina, oozing with liquid. Gingerly, she got to her feet, but nearly jumped back when something slid out of the huge orifice.

Slowly, she approached it, hearing low groans from it. It was absolutely soaked in Sweetie’s fluids like a thick, dripping coat of semi-clear goop. “H-hello?” Apple Bloom asked it, watching as it slowly pushed itself up. A pair of green eyes pierced through the ooze and stared at her, and suddenly, she recognized it. “M-Miss Cheerilee?”

Cheerilee stood up, slipping slightly but maintaining composure, and she glared harshly at Apple Bloom. “Why. Did no one. Tell me. To evacuate?!”

Apple Bloom looked at her, shaking a little.

“S-sorry ‘bout that.”

Author's Note

I decided to write some macro stuff involving Sweetie Belle, because the world desperately needs more macro stuff involving Sweetie Belle. Hope you enjoyed it.