Etna's Inflation

Hidden somewhere in a dank, dark forest, a demon girl sat atop a stump with her legs crossed and her head supported by her hand, sighing and staring off into the endless darkness. Etna was bored.
She appeared to be a young woman with bright red hair and a small, black outfit. A short skirt complimented by black stockings, a red, pointed tail, and a top that barely covered anything on her torso. Modesty wasn't one of her prime features, although that also had a little to do with what was keeping her mood down at the moment.
Etna didn't even rotate her neck to eye the figure who approached her from the west. She noticed right away the flowing blonde hair accented by a large, red bow, wearing somewhat of a white cloak with a red one-piece leotard underneath. It was Flonne.
Etna simply twisted her eyes to the left and let out a monotone greeting. "What do you want?"
Flonne seemed shy in her approach, unsure if what she was about to say would lead to positive results. "Uhmmm...hi, uhm, Etna, it's me, Flonne!"
Etna simply rolled her eyes and continued gazing forward, already disinterested. "Uh-huh..."
"See, I came to talk to you because, uhm...I heard you have a problem?"
Etna didn't have much of a reply to that. "Uh...huh..."
"I heard you were unhappy with, uhm, y'know, being flat-chested!" Flonne continued, trying to catch Etna's attention, which she did. Etna's head slowly rotated to gaze at the young angel, but with a look of raw hatred. Flonne could swear she saw a fire flaring up from her eyes. Etna was admittedly pretty much a board, but she loathed acknowledging it, and even more for others to point it out.
Flonne was a bit startled by the death glare, obviously hitting a nerve. "U-u-uh, w-well, see, I, uh, I have a s-solution!" Flonne grinned, hopefully avoided getting impaled in a second.
Etna's gaze shifted into one of doubtful curiosity. Her eyebrow rose and she eyed the girl, noticing her hands were behind her back, hiding something.
Flonne noticed the question on Etna's face and calmed, smiling genuinely and nodding. "Yeah, I came here with something that I heard was able to cure your dissatisfaction."
And with that, Flonne whipped her hands forward and revealed her surprise; a 16 inch round canister with several switches and a wheel on top, with what appeared to be a tube slithering out from somewhere behind Flonne.
The angel her her hands forward proudly, until Etna inquired further. "And...where did you get that?"
Flonne clasped the object close and grinned. "Uh-uh, it's my secret! But let's see if it works!"
Etna rose her hand up to her cheek and tilted her neck again, feeling a bit disappointed. "If...?" Flonne began to approach Etna as she continued. "How exactly does this thing wor-RRMMFF!" Etna exclaimed, suddenly finding the end of a long black tube in her mouth. Flonne had fished out the end of the tube and stuffed it into the test subject. The demoness already had a bad feeling about this. Flonne was...well, kind of a clutz. Her motives were pure but she acted with little regard. But Etna was too curious. She wanted a new bust. A huge bust. Even if it was only to amuse this ditz, she was willing to give it a shot. She bit down on the end of the hose and watched the device between Flonne's hands.
Flonne set the device on the dirt path and observed all of it's knobs. It seemed unlike any device either had ever seen, and Flonne's confused glanced told an already uneasy Etna that neither had any clue how to work it. But much to her surprise, Flonne quickly brandished a small booklet from behind her.
"Ooh, that's right, I have the instructions!"
Etna still sat in her dazed, bored position. She had no idea if this practice was going to end horribly or fail pathetically.
Flonne placed her hand on the largest knob, one protruding from the top, holding the booklet to her face with her other hand. She was reading intently, and began to read aloud. "Hmm hmm...okaaay...'To begin inflation'...hmmm hmmm hmm...'topmost valve'...hmmm...I guess that's this thingy..."
Etna's eyes became a little more concerned as she lifted her head. "Inflation...?" she questioned to herself.
The knob let out a loud, rusted creak as Flonne's hand spun it open. Etna's discomfort was beginning to grow noticeable, from the unsettling word to the decrepit state of the object in use. But before any of these concerns could be reasoned, she was hit with an incredibly more noteworthy happenstance.
A hissing began to echo out through the forest, the cylinder crying out like a snake as it began to work it's magic. A strange gas began to press its way through the tube and into the concerned vessel, pressing through her mouth and forcing its way down her throat with little hesitation. Etna's hands suddenly shot downwards, her body bolting upright and her legs pressing together, suddenly looking down at her body beyond the black tube in her face. Her eyes began to widen with concern over the next unsettling revelation.
Etna's body tingled with the sensation of gas that rushed into her. It cradled every inch of her skin, causing goosebumps to raise up, and invoking odd sensations through her body. What followed was obvious, but still rather striking; tightness. A pressure began to build as the gas was now holding up in every part of her, and with new gas continuing to fill her, and no where for the gas to escape, the next effect was easy to guess, but hard to believe.
Etna's body was expanding.
The gas that tickled every part of her skin began to press her from the inside, pushing her body out. First, she felt her skin tighten, followed by the gas filling up her limbs so tightly that her arms began to straighten, taut with air, even down to her fingers. Her stockings began to feel a little smaller as her legs began to get bigger. Soon her entire body began to feel this effect, as her skirt began to feel snug and her tiny top began to stretch.
Flonne looked up from her instructions, noticing Etna's cheeks puff out and her clothes seemingly shrinking around her petite frame. "Oooh, good, it's working! Now to figure out how to get a bigger chest..." She exclaimed, before sinking her nose back into the book, completely unaware of Etna's growing concern over her growing body, and also a bit forgetful that Etna's body is still continuing to inflate. Everywhere.
"Mmmmfff mmmm mfff!" is all Etna could respond with. She was now fully fearful of what could result from this gas siphoning into her, and sought to free herself from this rather unusual situation. Her first impulse was to spit the tube out, but it had a strange suction on her lips. The device seemed designed exactly for this purpose, even to torture innocent women, so she was a little less surprised by this. But this didn't stop her from pulling her puffy arms up and grabbing at the hose, grasping it with her pudgy fingers. However, this proved to be a wasted effort as her inflated hands simply didn't bend enough to fully grasp the hose, nor did any of her strength remain as gas pushed her skin outwards, turning her into a balloon. With one last effort, she tried to reach out and reverse the knob, stopping the device's insistent exhaling into her stiff body, but only before her arms retreated back to her sides, sticking outwards stiffly, absolutely tight with gas. She was trapped.
Etna's body began to shift as her legs stuck outwards, the skin near the top rising up like muffins as her legs were strangled by her increasingly tight stockings. Her hips gladly obliged in puffing up, her skirt becoming rather taut around her, the slit in the side revealing a growing curve atop her leg, joined by her rear end billowing outwards too. But all of this was a bit harder to notice when one particular feature was holding all of Etna's attention now. She could feel them. She could see them. Her top moaned as it attempted to stretch along her filling body. Two round mounds began to form beneath them. They were boobs. Honest-to-God breasts.
Etna's mood suddenly shifted. She was no longer full of fear, but instead that fear was now minor in comparison to her joy from seeing two generous curves lifting out from her chest. Her top quickly became too small to confine these two and her skin began to easily be seen from all sides. The skin of two balloons squeezed together by a top losing the battle to stay around her.
"Mmmmm! Mmmhhmmm!" Etna exclaimed in excitement. Her cheeks turned red. She was thrilled. Her body was suddenly bustling with joy. Although she was slow to realize the build up of ticklish gas was the reason, and soon began to grow 'too' excited. But she didn't care, she was happy to finally have an actual pair of breasts, and it continued to please her as they continued to grow.
Both girls were less mindful of the ballooning goth's gradually enhancing figure. The cylinder was turning the once small girl into a rather large, curvy demoness, and her small clothes were less than accommodating. With a loud rip, her small black top popped right off of her round torso, revealing two jiggling tits, which Etna was overjoyed by seeing. Her skirt was starting to lose it's sturdiness too, as the pumped-up thighs pushed downwards and revealed Etna's naughtier side. Her hips finally flared out enough to snap that in half as well, leaving her covered only by increasingly tight leggings, which began to snap and pop as each strand gave way to their inflating confines. What the girls hadn't noticed was that the ballooning girl was about twice as wide as normal, although a minor concern when Etna was watching her bosom blossom out to B cups.
Etna actually let out a giggle of joy. The tingling sensation was growing more and more intense. Her breasts bobbed playfully with each new inch of gas pressing them forward. They floated gently out, followed by Etna's feet leaving the ground. The gas was pulling Etna skyward. She let out a moan, her mouth turning into a smile. This gas was having an amazing effect on her. One word passed her mind: Bliss.
Flonne was surprisingly absentminded of the increasingly large Etna pulling away from the earth. She was studying intently on how to make the device do what she wanted, and was having a difficult time grasping how to handle it. She reached over to the device, pawing at it blindly until her hands met with a switch near several other switches. Strangely convinced that she had grabbed the only switch available, she flipped it, then her fingers rose up to the top wheel and began to spin it again. She was mildly convinced she had enabled the device to give Etna the bust she always desired. She hadn't.
The device breathing into Etna began to intensify her growth, suddenly pushing an unsettling amount of gas into the already overblown balloon girl. Her eyes widened when the peaceful tingling became buried underneath the sudden sensation of skin stretching. She felt her naughty bits begging for pleasure, but couldn't ignore the sudden pressure increase that followed. Etna was becoming more and more turned on, and was equally more and more terrified.
Etna's body was pumped full of an amazing amount of gas. The once petite girl was now triple her own size, and that number was increasing with each passing moment. Her breasts billowed out to the size of basketballs. A strange squeak echoed out from between Etna's legs as her thighs puffed up into each other, rubbing together and crying out in an odd sound. Her hips were equally rounded out, with a rear end that pushed up into her tail. Her stockings were quick to rip in half and drape around her feet, leaving her a naked, inflating balloon girl.
Etna wanted to cry out, but didn't know how to react. Each passing moment caused her to feel more and more excited, but also felt pain from her skin resisting its unnatural growth. Feelings overflowed in her as her body overflowed with gas, every inch of her now puffed up to five times normal size, with the exception of her new amazing bust that protruded forward 3 feet, and her lower body which curved outwards in a way that matched her ridiculous chest. Her body let out several loud creaks as her inflated skin pressed into other parts of her body. She wanted to simultaneously free herself, and never stop. And she kept growing. And stretching. And inflating.
Flonne sighed and scratched her head, defeated by the complicated machine. Without much hesitation, she quickly tried to pass the instructions onto her partner. "I'm afraid I don't get how...this..." Flonne trailed off. She noticed Etna's sudden disappearance from the stump she was sitting upon earlier. The angel stared in confusion until she noticed the hose from the device floating up into the sky. Her eyes followed the slithering tube's ascent until she noticed the giantess floating above her. Etna was now a massive balloon, with a 5 foot bust.
Flonne simply began to stare at the pumped up Etna, watching her body expand rapidly. After a moment, her eyes lit up, and she smiled. "Yeees! Yes yes yes! It worked! I did it! You have a wonderful chest now, Etna!"
Etna would gaze in amazement of her naivety towards this situation, if only she could concentrate on anything other than her, frankly, embarrassing predicament. She was a massive parade float of a woman, unable to move and becoming dangerously taut all around, and Flonne had perceived this as a positive. Etna's body was completely engulfed in fear when Flonne placed her hand upon the valve of the device. "No more!" She cried to herself. She closed her eyes as best she could as the valve began to turn.
Thankfully, Flonne was just smart enough to know that Etna was large enough. The ringing hiss of the cylinder sputtered to a stop as the gas' assault on Etna's titanic body ceased. Now, simply bobbing at the end of a tube, like a balloon strung to a child, Etna's body quivered and shook in the air as a gentle wind caressed her body. Suddenly, the float was at peace. The tingling sensations calmed as silence fell upon the forest, followed by the squeaks of two gorgeously huge breasts pushing into each other.
Flonne's eyes perked up as she remembered her next step. "Ah, yes, let me get that out of your mouth!"  With the flick of a switch, the suction of the hose loosened, and out from Etna's lips fell the device. And followed soon after, a massive gust of air.
Etna's eyes shot wide open as the gas inside her body raced towards the now open gap in between her lips. It fought so hard for room in her that it immediately sought escape, and with the force that pushed from her mouth, her light-as-air body did little to resist being flung backwards into the forest. Like a rubber ball thrown into a cage, her body bounced wildly as it ran into several tree trunks, rebounding off and sending her deep into the woods.
When she was heavy enough to approach the dirt, her body slid across the leaves, flying rear first into a tree that hit directly between her legs, and her severely deflated body didn't appreciate it. With one desperate effort, she clasped her now mostly deflated hands around her mouth, trying to keep from deflating further. When the hiss stopped, she was laying across the ground with her legs poised around a tree, her naked body slightly puffed up, but her joyous new bust was gone. She simply sighed in defeated and breathed out the last of the gas. The once again flat Etna stood up and examined her body, seeing it once again as a boring, flat canvas. Her cheeks were red for several reasons, but her whole face grew blood red with fury.
"DAMNIT, FLO-" Etna called out before suddenly clenching her teeth together and stopping herself. Her voice was suddenly many octaves higher than normal, her speech squeaky like a cartoon character. Her face retained it's hate-filled glare as she stomp off, silently vowing to make Flonne pay.