Sister Secrets

"Welcome back, sis!"

She heard Amanda, her younger sister and roommate warmly greet her as she closed and locked the front door behind her.

"What the…Amanda-"

She immediately began to giggle incessantly interrupting her, sitting at the kitchen table with her big bare ass touching the chair.

She was barely clothed besides a bright red pair of lingerie that was way too small for her thick and luscious thighs and now a much larger bubble butt.

Her body had grown to absolutely tremendous proportions.

Her huge round bubble butt was engulfing her bright red underwear looking more like a tight thong.

"Mmm…what do you think?"

She ran her long fingers down her incredible cleavage spilling out of a tight tan blouse, barely able to stay contained at their new much bigger size.

"What happened to you?"

Emily approached her, dropping her bag down by the couch as she got closer.

She only felt smaller and smaller.

Starting to realize just how big she had grown.

"Oh, you mean these new big and lovely breasts?"

She pressed onto her chest with her palms squeezing her breasts together until her tender nipples began to get hard growing to the size of two large round buttons.

"Nngh...oh yeah…mmm…they are so sensitive..."

She cooed, squeezing them tighter and harder starting to bite down on her luscious lower lip.

They suddenly bulged even bigger, stretching out the fabric of her top even further creating even more bubbly cleavage.

"Did they did they just-"

Amanda interrupted her squeezing them tighter as she grinned devilishly giggling even more as the rest of her jiggled in succession just by nodding enthusiastically.

"Get bigger? Yes!"

She cooed some more, cutely letting out long stifled moans as she looked down at her bubbling chest watching it swell and grow larger.

She held onto them tightly rumbling before her entire body joined in and suddenly jumped upwards growing larger all at once.

Her tight panties began to tear a bit as she filled out swallowing up more of her already strained undies into her ass.

Her top on the other hand was now really starting to strain as the sleeves were now about halfway down her forearm.

The open gap between her two bountiful breasts was even further down her chest and wider by her shoulders.

"Ooh…more of that too…mmm…"

Amanda blushed looking down at her tender nipples pressing even more against the tightening fabric of her skin-tight top.

"What the fuck is going on with you?"

Emily was green with envy seeing Amanda's huge tits still growing from her big secret she didn't want to mention it to her sister.

She smiled, placing her hand on her chest as they bubbled up slightly bigger again.

"Ooh…there it is again. It started like an hour ago and I've already gone up like three or four cup sizes, it's fucking crazy, but I guess I did take a bunch…"

You could see the top of Amanda's head rise up higher every so often as she continued to grow in small short spurts slowly gaining height every so often.

"What the fuck are you talking about? What did you take? Did you even measure yourself?"

She looked back up at her feeling another short growth spurt make her big booty plump up growing bigger.

She let out a soft moan as her eyes widened hearing her reach the end of her line of questioning.

“Oh! I didn’t think to do that, wait, hold on, let me stand up.”

Emily crossed her arms scoffing in disbelief as her jaw dropped watching her sister slowly rise up from her chair.

She rose up and up, taller than she had expected.

Watching her head rise up and over her head, as she stood all the way up and looked down at her smiling with a wholehearted grin.

"Oh…my god."

Emily was baffled unable to accept the fact that her sister had completely outgrown her.

Amanda had grown so much, but she had no idea she was getting taller until just now.

Coming upon the realization had made her extremely horny thinking to herself.

"She looks so short, fuck…I didn't realize this stuff would make me grow taller too…this is amazing!"

She stood there for a moment panting heavily as a trickle of her precious juices began to drip from her soaking wet vagina slowly.

Her sister Emily didn't even reach her chin now, she was already a whole head taller than her and she wasn't even close to being done growing yet.

"Whoa…you look…like…really short now."

Emily couldn't help but scoff audibly as Amanda motioned her hand out laying it flat and lowering it down onto her head.

She rolled her eyes and sighed audibly watching her intently measuring it against her newly grown body, seeing it line up just under her chin.

"You're huge! What the fuck!"

Amanda couldn't help herself, she giggled and smiled wider seeing her now half-a-foot shorter sister getting heated.

"I can't believe it! I'm a whole head taller than you now, this is awesome, haha!"

Emily was starting to get embarrassed and extremely emotional, rolling her eyes like a slot machine again and again listening to her giggle and moan jiggling all over.

“Go over there, so I can measure you…”

Amanda bit her lip and giggled responding cheerfully excited to know her real height now.

“Okay, okay! I'm sorry Emily…I'm just so happy it's actually working, it feels so good to grow.”

She refused to crane her head up to make eye contact with her now super-sized sister, as she would be forced to also look at her huge swollen nipples on each of her humongous fluffy breasts.

"Whatever. Just go over there already."

Emily began to fume with jealousy seeing her super-sized sister waltz casually over to the living room, her huge ass bouncing from side to side as she stepped toward a large measuring tape stretched out on the wall.

Her jaw dropped, reading her height at the size foot mark.

"What the FUCK! You’re SIX FEET TALL?! We used to both be the same height, five foot six! Are you telling me you grew over half a foot taller in an hour?!"

Emily was fuming, she practically had smoke billowing out of her mouth and ears.

Amanda blushed looking down at her feeling another wave of growth wash over her making her feel slightly faint.

“Huh…that’s strange…mmmhhh…more...”

She rose again, starting to dig into the six-foot-tall size exponentially growing slowly as her head rose up higher passing the half-inch mark toward the next mark.

"And now that you mention it…he did say taking more than one at the same time might have some unintended side effects."

She smiled as she bounced up again growing another inch taller now passing six foot two as she watched her sister and the rest of the room shrink even smaller.

"But…he did say it would make me grow faster! Haha…mmm…it does feel really good you know…I bet you would love the feeling too."

Her body only rose higher as her vision sunk down past her face seeing the edge of her huge breasts rising up closer as she grew past six foot three.

"Uhh…I don't know what you're talking about... but…you're still getting bigger…when is it supposed to stop?"

She could hear her sister trying to hold back her laughter as she replied.

"Gosh…I don't know…I hope it never stops…it feels so good."

Her older sister suddenly felt a chill run down her spine hearing those words and looking up at her taller now more powerful sister towering over her smaller body.

"I just love…growing…awhn…yeah…."

The feeling began to boil inside of her trying to hold back, but Emily finally started losing herself in a flurry of jealousy.

"Are you fucking crazy? How are you going to fit in your bed? What are you going to wear?"

Amanda was soaking up her envious rage looking down at her and smiling wider as she began to feel the sensation build again even stronger than before interrupting her with a roar of pleasure.

“You’re so…JEALOUS! Mmm…FUCK YES…MORE…BIGGER…awhn!”

She was interrupted again hearing her moan loudly as she witnessed her body rumble for a moment jiggling all over.

Her shorter sister's perspective began to sink lower.

And lower.

As she grew.

And grew.

Growing taller and taller.

Sending her older and now much shorter sister's perspective plummeting down past her head and into her wide expanse of ever-growing cleavage.

Her blouse rode up her belly and then up to her chest as it stretched out to the extreme.

Her red panties finally tore off as well, dropping to the floor under her ass which grew more and more, bubbling up bigger and bigger.

It became absolutely enormous engulfing the space around its overwhelming jiggliness.

Having grown another half a foot taller now made her sister look truly tiny beside her new incredible size.

"Oh, my god…”

She bounced up and immediately squealed with immense joy.

"Eee! I grew way more than last time! That was at least three or maybe even four inches! Look at you all the way down there, haha!"

Amanda rolled her eyes barely able to withstand the embarrassment of now being a foot shorter than her younger sister.

"Mmm…and these are getting bigger too."

Her breasts continued to plump up bigger growing another whole cup size larger and bulging in front of her now much tinier sister staring face to face with them.

"You're getting huge! What the fuck!"

Her short sister's perspective quickly began to sink lower again as her younger, but now much bigger sister began to rumble with growth again.

She boomed with size surging with growth all over as her breasts ballooned in size and her chest rose up higher and higher as she quickly grew into a seven-foot-tall amazon.

"And you're just getting smaller! Hahaha! You look so cute down there."

She smiled letting out a cute gasp as her top began to tear apart growing another few inches upwards.

"Oh no…no…no…'

Emily backed up seeing her lurch up several more inches closing in on seven and a half feet tall.

"Awhn…nngh."

She gulped nervously seeing her two enormous breasts now at her eye level.

"Oh fuck…"

Emily was nearly speechless having to now crane her head all the way up past her humongous breasts just to see her devilish grin staring back.

"Wow…I'm going to start calling you my little sister from now on, hahaha!"

She bellowed out a powerful laugh, heckling her as she placed her large hand on her head measuring her height now under her tremendous cleavage.

"Aww…you aren't even as tall as my big titties…little sis'.

Emily began to turn red, gutting extremely embarrassed.

"This is insane…what did you even take to grow like this? I mean those are the biggest fucking titties I've ever seen!"

She spits out the question, finally giving into her new super-sized sister's new super-sized ego.

"Mmm…can you keep a secret?"

She looked intimidating at her new tremendous height, looming over her towering over her head by two feet.

She nodded looking desperate, biting her lip and looking past her enormous nipples that were like two round pieces of hard candy begging to be sucked on.

She had never been this submissive before, Amanda started to play with her long auburn hair, motioning her hands down across her face.

"Well…you know I work for a pharmaceutical company, they've been developing a new performance-enhancing drug."

She stretched her long arms over her head, shoving her huge breasts in her face without warning.

"The thing is…nngh..."

She started to grow again rising up slightly higher an inch as she continued feeling a bit distracted by the tingling sensations running up and down her legs and thighs.

"They haven't tested it on any women…they didn't want to…mmm…"

She let out a deep moan, wrapping her arms around her, smothering her with her luscious soft breasts.

"So I took some…"

She let out a mischievous giggle hearing her begin to lose their breath stuck inside her incredible cleavage.

"After growing into this…absolute amazon…I can see why the board didn't want women using it…we would be unstoppable. "

She let out a maniacal laugh slowly releasing her from her smothering grasp hearing her let out a loud gasp trying to breathe.

"Augh! What the fuck! Oh my god, I couldn't breathe in there at all, Amanda!"

She towered over her, still hugging her around her back, forcing her head to be right up against each of her luscious breasts.

"Relax…I wasn't going to hurt you…mmm…I just wanted to test out my new size."

She reached under her arms whisking her up and above the carpet with ease.

"Ah! Put me down!"

She smiled coyly, lifting her up and down comically without any trouble.

"I mean look at this, you're as light as a feather now, I could probably throw you across the room."

She looked back at her with fright mumbling slightly before speaking up with two big puppy dog eyes.

"Please don't…"

Amanda couldn't help herself, laughing again, placing her back down on her feet and then immediately smothering her with her enormous chest.

"You are just too CUTE! I can't stop hugging and squeezing your tiny little itty bitty body."

She couldn't even speak feeling her lips and face smashed between her luscious soft breasts, engulfing her head between their new incredible size.

"Imagine a whole world full of super-sized women, we would be in charge, they wouldn't be able to stop us, and they couldn't say no to us at this size."

Amanda was soaking wet, she could feel trickles of her cum oozing down and onto her thighs, clasping them together to avoid dripping onto the carpet.

"Awhn…god I'm so horny…I want to see you grow…do you want to get bigger?"

She smiled hearing her gasp again, letting her out of her literal booby trap.

"Yes, please! I want to grow, please…I'll do anything."

Emily begged her for it, feeling her two huge breasts pushed up against the sides of her cheeks, barely able to respond, still hugging her tightly.

"Anything…?"

Amanda was about to erupt hearing her older sister powerless stuck inside her now enormous overflowing cleavage begging her to grant her the same god-like physique she had grown.

Her eyes rolled back finally unleashing a powerful orgasm as Emily watched her tremble.

Her body grew and grew, hearing her moans loudly echo out before rising up another half a foot taller.

The rest of her ruined clothes finally began to tear off into shreds leaving her naked body spilling with towering curves.

She released a wet stream down her tremendous thighs watching her sister getting smaller under her now eight-foot-tall body.

She was tremendous.

She had grown into a real-life Amazon warrior with big muscles, huge bouncy breasts, and an ass that could crush a man's head like her tremendous thighs that could easily smash a watermelon now.

"Awhn…fuck that was good…"

She sighed, moving her hands down to her own pussy to get a taste of her wetness.

Emily was appalled, acting disgusted, yet extremely turned on, her perspective was now facing the bottom of her belly near her waist.

She felt so small.

She wanted to grow too.

Amanda sighed, moving away from her, and ruffling her long golden blonde hair, before stomping down the hallway watching her hair wave side to side just above her giant jiggling ass.

She looked over hearing the thumping of her now huge body making things on the tables and countertops shake and tremble.

"Wait, where are you going?"

Emily turned, seeing her gigantic ass bouncing from side to side.

"That's all I wanted, I'm going to take a shower."

She was confused looking up at her with envy blazing in her eyes.

"What? What do you mean? What about the pills?"

Amanda laughed, turning around for a moment just to spite her.

"There's none left, I have to get back to the lab and get some more, sorry sis!"

Emily stood there fuming, waiting for the time she would strike back.

And get her revenge.