Kayla hated her brother. Well she didn’t hate him but she did wish he’d grow up a bit. He loved nothing more than to tease Kayla, primarily about her height. Look, it wasn’t her fault she was in her senior year of highschool and barely over 4’10. Her brother, on the other hand, stood at a cool 5’7. Still not tall by most standards but to Kayla he may as well have been a giant. And he never let a day go by that he didn’t remind her of that fact.
“Hey shrimp, pass the salt. Oh, I guess your arms aren’t long enough haha!” or, “Need me to grab the ladder, Thumbelina? The faucet’s really high up!” You know, shitty sibling stuff. Things got a little better when he went off to college, only because he wasn’t always around to mock her.
But now he was coming home for the winter break and he’d been bragging on and on about how he grew an inch to 5’8. What the hell’s so great about growing one measly inch anyway? I bet he’s lying and just measured himself with his shoes on or something. Kayla brooded, she was so lost in her thoughts that she almost didn’t hear the light “ping!” from her phone.
Picking up the offending device she just caught a notification that something had been installed. What the hell? She pursued her apps looking for something new until she came across an odd item simply named “D.Jiin Ver.0.2.15”. There was no image, just a blank space and the text. Hella suspicious by any reasonable standard but something about the name caught Kayla’s curiosity.
Upon opening the app she was prompted to allow access to her microphone, she was so used to accepting these agreements that she’d tapped “Allow” before her better judgment could kick in.
“Dammit!” she swore, now who knows who was probably listening to her every word.
“What’s wrong squirt?” Her brother barged into her room, fresh from the airport. “Did’ja get even smaller or somethin’?”
“Jack, what the hell. Could you at least knock?”
“Nah, I wouldn’t want to make you reach all the way up to the doorknob anyway!” Kayla just rolled her eyes as she stood up. She knew she couldn't force him out of her room, nor could she intimidate him but if she were going to deal with his shit she would do so standing up. Of course this sentiment was somewhat soured by the fact that she was actually shorter standing than she was sitting on her bed.
“Just, get the hell out will you? I have to change for dinner.”
“Yeah, yeah, the munchkin’s gotta play dress up sure, sure.” This last statement stung Kayla in just the wrong place, she hated being compared to a munchkin.
“You know what? I really wish you knew what it was like to be the short one! Maybe then you wouldn’t be such a shit head!” As soon as she had finished yelling at her brother there was a “ping!” from her phone and the whole room seemed to become a swirl of colors. Kayla stumbled backwards as she experienced a strong sense of vertigo, the feeling was so intense she felt she might vomit. Just as quickly as it had begun the strangeness stopped. Kayla blinked, trying to make sure that she could in fact see normally. Everything seemed normal, except her brother was gone.
“Jack? Where’d you go? Are you hiding?”
“Ha ha, very funny.” A voice rose from just below Kayla’s sightline. She looked down at the figure at the lower edge of her vision.
“Jack? What the hell! You’re so small!” She almost laughed at the sight of her now diminutive older brother. He had to be just as short as she used to be! But that meant she was taller too! Kayla confirmed this, observing her room which now seemed so much smaller than it had before.
“Give it a rest will you? Oh yeah, let's make fun of Jack! He’s so short, his little sister’s taller than him!” Jack spoke in a cartoonish voice as if to imitate his sister. This annoyed Kayla. If he’s so short, where does he get off making fun of me? She thought. Nevermind the fact that he seemed unaware of the changes, he should still show her some respect! That’s when she got an idea. She wasn’t entirely sure what had caused these changes but she was willing to hazard a guess. But for her plan to work she’d have to make a few more changes before going all out, also, she wanted to have a little fun.
“Say Jackie, before you go did you manage to ask out that girl you mentioned?”
“W-who, you mean Erin?” Jack’s voice and demeanor betrayed his attempts at casual conversation, giving him the look and sound of a nervous teenager.
“Yeah! She was cute! A few inches taller than you though. Probably stronger too, she probably wouldn’t go out with a midget like you, what a shame.” Kayla grinned widely as she stood closer to her brother, bringing his head level with her shoulders, as if to emphasize her words. Looking down at his little body she could see him clenching his fists in what she first thought was rage, but as he turned away she caught a glimpse of what looked like tears streaming down his face. Oh shit, did I go too far? For a moment she was tempted to reverse the changes but then Jack opened his big mouth.
“Yeah so what. No one would ever want to go with you either, you giant freak!” He spat the words at her like venom and her thoughts of sympathy melted at their touch. We’ll see about that. Now was the time to test her theory. First, if she was going to be a “giant freak” she might as well go all out
“I am pretty tall but, I wish I was even taller and that you were even shorter!” She was taking a gamble here by being so vague and she knew it but what was life without a little spice? Immediately the swirling colors and vertigo returned. This time when it was done Kayla noticed the difference immediately. Her 7 foot ceilings were mere inches from the top of her head. Meanwhile her brother had all but vanished, she looked down to find his tiny frame level with her stomach.
“Why? You’re already taller than like every guy I’ve ever met. And I’m tiny! I’m not even 4 feet tall. Why would you want me to be shorter?” his attitude seemed to have changed from spiteful to almost admiring. Kayla squatted on her heels to be level with her little big brother.
“And that’s the way it’s always been?” She asked, probing for an answer. Jack blushed slightly and turned his head away.
“Y-yeah. You were taller than me by the time you were 4 since I stopped growing when I was 6.”
“Aw, poor little guy!” Kayla patted her brother’s head and pulled him into a hug. Then she whispered. “But you know, I wish I was Erin’s ideal woman. At least then someone could satisfy her.” As she said this the room swirled but this time the sensation was different. Her chest grew hot and heavy and there was something strange going on between her legs. Jack was pushed further and further away as her chest expanded at a breakneck pace. When it was finally over her 6’8 frame was sporting a pair of beach ball sized tits, each probably outweighing her brother.
As she stood she watched Jack’s face disappear beneath her chest, and the “other thing” made itself known.
“K-kayla! Put it away!” Jack stammered and backed away slowly, staring at her crotch.
“What? This lil’ thing?” Kayla sang as she swung her hips, causing her newly grown cock to slap against her thighs. It was hanging between her legs well past her skirt. Off the top of her head she assumed it was roughly the width and length of Jack’s, admittedly small, arms. Jack's face flushed bright red and he turned to run away.
“I wish you’d stay!” Kayla yelled quickly. Almost immediately Jack stopped and turned around. Kayla smiled mischievously. “Why don’t you show me yours Jackie? That is, unless you're intimidated by your little sister’s cock?” As she said this a range of emotions passed over Jack’s face, finally ending on determination.
“Fine!” He slowly started taking off his pants.
“I wish his dick and balls were tiny even for his size!” Kayla whispered into her phone, the soft “ping!” was like music to her ears. Jack finally stood before her naked and Kayla peered closely. She was just able to make out a tiny twig flanked by two marble sized balls. She reached forward with a single finger that easily dwarfed the micropenis. She had barely even touched it when a minute spurt of white liquid landed on her finger tip. She held the finger to her face, barely able to make out the pathetic offering before breaking into uproarious laughter.
“That’s your dick? Bro, even a fetus is packing more than you!” She stood back to her full height and slipped off her skirt, simultaneously whispering “I wish I had the biggest set of cock and balls in history” She suppressed a moan as she felt her already large dick expand further. Now, not even hard, her mammoth cock was over 18 inches long and each of her balls was larger than her brother’s head. She heafted her dick and placed it on her brother’s left shoulder where it hung over his back. He visibly faltered at the weight of his little sister's penis, needing to shift his feet in order to maintain balance.
The sensation of her brother’s skin against her own sent chills down Kayla’s spine and her cock pulsed as it filled with her blood, stretching ever longer. By the time her 36’ member had reached it’s full size it was nearly as long as Jack was tall.
“Hmmm, I wish he was at just the right height!” Kayla whispered. Rather than having Jack shrink, the app chose to have Kayla grow. Both she and her cock increased in proportion. Thankfully her ceilings seemed to increase with her so when she reached her final height of 9’10 her head was still a couple inches from them. Jack, who was now both shorter and narrower than Kayla’s thighs, had to look up at her titanic 5 foot long dick. It was more than a foot longer than he was and as thick as his shoulders were wide. Kayla’s testicals were nearly the size of beachballs and almost certainly outweighed Jack’s tiny frame.
Kayla slowly pressed her cock down with one hand so that its tip hovered just in front of Jack’s face.
“Hate to break it to ya little guy, but I’m the ‘man’ of this house.” Once again Jack turned red and looked away. What had he been thinking? Comparing dicks with his little sister? She’d always been taller and had a far bigger cock than him and loved rubbing it in his face, literally. As if reading his mind Kayla took a half step forward, causing her dick to touch the side of Jack’s face. The contact prompted a slurry of precum to drench his upper torso. Kayla got another idea.
“Kayla what the hell-”
“I wish you’d suck me off whenever I asked.” Kayla didn’t bother whispering this time. At first it seemed like nothing happened. She looked down at Jack’s stubborn face. “Well?” She probed. Jack just mumbled something under his breath. “Speak up squirt.”
“You could at least ask….nicely?” Jack looked up at her apprehensively. The uncertain look on his face sent pangs through Kayla’s heart. He’s so cuuuuuute!
“Alright then. Will you suck me off? Please?” No sooner had she spoken than did Jack step forward to kiss the tip of her penis. It was far, far too big for him to fit in his mouth, the tip alone was larger than his head, so he gave it his best effort. Kissing, sucking and caressing her dick from tip to base. The feeling was heaven for Kayla, she’d never experienced pleasure so intense. Just before she was about to cum she gripped Jack’s head and held it firmly in place at the end of her cock.
“I wish he’d swallow everything!” She gasped between breaths. As she ejaculated gallons of cum Jack clung to her cock, diligently slurping and swallowing every last drop. Even as his stomach distended and semen started leaking from his nose he kept at it. Finally the torrent came to an end and he fell onto his back, his stomach stretching past his bent knees. Kayla looked down at him fondly. She bent down and hefted him into her arms, she couldn’t be sure but it felt like the addition of her cum and more than doubled his weight. She placed a wet kiss on his sweaty forehead and walked towards her bedroom door, cradling him like an infant.
Kayla loved her brother.