As you walk in to your step-dad's house,your greeted by the usual yelling and crying that goes on between your step-sister's Kelsey and Kylie.Since their dad and your mom are on vacation for the week you have to watch the house to make sure Kylie and Kelsey don't wreck it.You're 17 and about 6'0",Kelsey's 16, and Kylie's 15.

"Get off me!I just want my cd player!!" You hear Kylie yell from upstairs followed by a series of loud bumps.You walk up stairs and into Kelsey's room to find Kylie on the ground with Kelsey's foot planted on her head holding it down.

"Your gonna have to ask nicely." Kelsey says in a taunting voice holding the cd player above Kylie's head.Kylie is 5'7",very tan and has a thin body and face with light brown hair and very defined facial features.But she's no match for Kelsey who is about 6'2", has a very athletic,almost muscular body,and a roundish face with blonde hair.

"Kelsey, let her up." you say in a comanding voice.

She obeys with a smirk and lifts her foot off Kylie,Kylie gets up quickly and grabs her cd player from Kelsey.

"Whats going on now?" you ask.

"She stole my cd player!" Kylie shouts at you,she then starts slapping Kelsey in the arm.You get inbetween them just as Kelsey starts to go after Kylie,you have some trouble holding her back,she's pretty built for a girl but you figure soccer,vollyball, and every other sport she plays aren't gonna do anything else to her.

"Come on Kelsey,chill." you say to her,but it's like trying to stop a bull,and before you know it Kylie is trying to slap her over your shoulder.

"O.K. thats enough!!'' you shout,you give up on stopping Kelsey and turn to Kylie and start to push her out of the room. "Kelsey,you wait here." you shout as you lead Kylie to her room.

You walk her into her room and sit her down on her bed,she starts to tear up.

"Can't you do anything about this!" she shouts and starts sobbing.

"Listen,Kylie i'm sorry but I can't control your sister." you say trying to comfort her.

"I know,but couldn't you make something that could even the odds a little bit?" her crying lets up.

"What do you mean?"

"Well,your smart,can't you invent something that will even out the size difference in me and Kelsey so she'll stop bullying me"?

You sigh,"I don't think so." You leave her room and go to Kelsey's room,she's still standing were you left her.

"So,the brat wants to be bigger huh?" she says to you with a smirk.

"Kelsey you really have to stop being so mean to her." you say.

"Well, what are you gonna do about it,i'm bigger than both of you,"she pushes you and you fall onto your back in the hallway,she sits on your chest and spreads her legs so that her cunt is near your face,you can smell it through the soccer shorts she has on, "and unless you make some magic growth ray thats not gonna change." She says with a laugh. She gets up and walks into her room. "Good luck." she says with a laugh and slams the bedroom door.

"Guess I better get to work then." you say under your breath.

You wake in a daze trying to remember were you are.You look around and realize your in the girl's basement to your left you see a device that looks like a remote but with to prongs sticking out of the front like a tazer,there are three buttons,Size,Height,and Strength.You realize this is the growth ray you built last night and you must have fallen asleep working on it.It needs a little tweaking though so you get back to work,about 20 minutes later it's complete.Just in time too,Kylie and Kelsey are fighting again.

You walk up stairs with the shrink ray in your pocket,again the girls are yelling at each other,this time in Kylie's room.

"Hey Kylie I need to talk to you in private." you say.Kelsey storms out of the room and slams the door behind her.

"What do you need." Kylie says in an agravated voice.

"Well,remember when you said you wanted to be bigger than Kelsey," you say as you pull the device out of your pocket "I think this will help."

"Oh my god!" she says in disbelief.

"Yeah but I haven't tested it so we'll have to take things kind of slow for now."

"O.K." she says in agreement.

"O.K." you say "Stand up straight and look at the ceiling." She follows your command. "O.K. get ready." you point the device at her and press the prongs against her stomach,you hold down the button that says height,Kylie is surrounded by a glowing green color ,you hold the button down for about three seconds and Kylie grows three inches.

"It works!" she says with exietment.

"Do you feel ok?"

"Yeah,my clothes feel a little tight but I'll live." today she's wearing a tight fitting blue abercrombie and fitch shirt with capris and white slip on vans.

"O.K. since you only come up to about Kelseys neck,we'll make it so she only comes up to your neck."

She looks at the ceiling again and you touch the prongs to her stomach,this time you hold the button down for about 18 seconds,she begins to glow again and starts to get taller.

"This feels great!" she says as she slowly rises."My clothes are starting to get to tight." she complains at about 6'4"as she keeps growing."Ok they really hurt now." she says in agony she is now 6'8".Her shirt is climbing up her torso and is a little bit over her belly button,her capri's are ripping up the sides and crotch area,her shoes are ripping at the toes. She keeps growing and at 7' her capri's are so ripped they fall off her body,her toes and her heel are sticking out of her shoes,they are just barely hanging on her feet,she finally hits 7'6",she lifts her feet and her tattered shoe fall to pieces on the floor,she rips whats left of her panties off and then rips her shirt and bra off at the same time.

"Now to have some fun." she says with a wicked smile.

You follow behind her as she walks out of the room,she has to duck to get through the doorway,she continues down the hall towards Kelsey's room.

"What are you going to do to her?" you ask,you almost have to jog to keep up with her.

"You'll see." she says still smiling.Kelsey's door is shut."Oh Kelsey,I have something to show you." Kylie says knoking on the door.

"What do you want brat?" Kelsey says as she opens the door,her eyes become wide and her mouth hangs open,"What,what happened?" she asks in disbelief.

"Lets just say I had a growth spurt and now your gonna pay for all the years of bullying me." Kelsey backs away slowly as Kylie makes her way into the room, you walk in behind her and set the device on an end table.

"Where are you going," Kylie asks in a taunting voice,"Don't you want to play?"

Kylie grabs Kelsey's arms and thrusts her to the ground.

"Kylie stop!What are you doing!?" Kelsey yells as she struggles to break Kylie's grip.Kylie sits on her stomach to stop her struggling.

"Only what you've been doing to me since we were 10." Kylie yells back angrily,she puts both her feet on Kelsey's face.

"Remember all those times you did this to me?" Kylie asks,she shoves her right foot into Kelsey's mouth. "Suck them." she says in a comanding voice. Kelsey obeys and starts to suck,her mouth can hardly contain Kylie's huge foot. Kylie laughs eviley.

"You know all this fun turning me on," Kylie moves her crotch from Kelsey's stomach onto her face."I want you to eat me."

"I never did this to you!" Kelsey shouts in a weak voice.

"True but it will make up for four years of putting up with you." She says as she moves her pussy closer to Kelsey's mout.Kelsey holds her mouth shut tight.

"Do it," Kylie comands as she wraps her legs around Kelsey's head. "Or i'll crush you."

"O.K." Kelsey says, tears running down her face,she opens her mouth and recieves Kylie's cunt.Kylie tilts her head back and moans as Kelsey eats her.

Kylie squeezes her legs together,"Use your tongue." she gasps as Kelsey obeys,she is now sobbing.

"I think I've had enough from you." she says to Kelsey with a smirk,she stands up and puts her foot on Kelsey's head."Now I want some of you." she says to you,she walks over to the device and presses it against her breasts and hits the size button,she moans as her breasts glow green and swell up to the size of your head. "I think I should repay you for helping me." she says in a seductive voice,she bends down and wraps her arms around your waist and slings you over her shoulder.

Kylie walks you down the hall and into her room,she sets you on the edge of her bed and sits on your crotch.

"Ow what are you..."

Before you can finish she gives you a long kiss and then begins to unzip your pants.

"Whoa wait your underage, and what if Kelsey comes in?"

"Oh I doubt Kelseys gonna come anywhere near me after what I did."

With that she mounts you and begins to thrust up and down your shaft.

"Ooooh." she moans and then giggles.

"What are you laughing at?" you question.

"Haha well it's just i'm really big now and um... I can hardly feel you."

"Well if im so tiny use the growth ray." you say angrily.

"Oh yeah good idea, but where did I put it..."

It dawns on you that she left it in Kelsey's room.

"...uh oh." she sputters.

"Uh oh is right." you hear Kelsey's voice boom from outside the door, you can hear her footsteps booming as she walks down the hall.You stand up and reach for the doorknob but before you can Kelsey crashes through the door. You turn to shield yourself from the shards of wood.You turn around to see Kelsey's bare crotch,you follow her body up almost to the roof, she is staring down at you with a wicked smile and you figure she's about twelve feet tall. Before you can react she smashes her hand into your stomach, squeezes, and hurls you up in front of her.

"I guess I should thank you too." she says laughing, she squeezes you hard which makes you gasp and while your mouth is open she presses her against it. Her mouth is covering the entire bottom half of your face, her tongue shoots into your mouth and slowly creeps into your throat, you can feel it slither down and before you know it it's half way into your throat and your suffocating. You struggle to free an arm but her grip is to powerful and the more you fight the more she clamps her mouth down. Afer what seems like forever you feel her tongue slither out of your mouth. You cough as you try to catch your breath.

"Awwww whats the matter can't catch your breath." she says eviley, "Maybe you'll breath easier down here.'' she drops you onto Kylie's bed then puts her foot onto your face,the ball of her foot is covering your mouth while her toes are directley under your nose.

"Kelsey!Get off him!" Kylie shouts as she punches Kelsey's leg.

"Haha looks like someone needs an attitude adjustment." Kelsey removes her foot from your head and starts toward Kylie.

"Stay back!" Kylie says as she backs away from Kelsey, but Kelsey keeps moving forward."I'm warning you!" Kylie yells fearfully, she throws a punch at Kelsey's stomach but it's useless, Kelsey flexes her abs and Kylie's punch bounces off her six pack.

"Nice try." she scoffs as she wraps her hands around Kylies waist, she spreads her legs and slowly raises Kylie toward her cunt.

"Noooooooo!" Kylie screams as her head dissapears into Kelsey's pussy.

"Mmmmm." Kelsey moans as she moves Kylies head in and out of her pussy. "Your better than my dildo.

After about 2 minutes Kelsey stops thrusting and pulls Kylie's head out of her pussy.Kylie is gasping for air as she coughs up fluid from Kelsey.

"And now it's your turn." Say Kelsey as she turns toward you, she picks up the shrink ray as she walks toward you.

"What are you gonna do to me?" you ask in a fear filled voice.

"I'm gonna have some fun." she sasy with a wicked laugh, she pushes you to the ground and mounts your cock. "Tsk tsk this won't do your much to small for me."

You gasp for air as she sits on your hips, you figure she must weigh around a thousand pounds because your hips feel like theyre going to break.

"Thats ok your handy little toy will fix that." She stands up a little so she can put the device on your cock, she pushes the button and your cock swells up inside of her.

"MMMMMM thats much better." she moans, your dick is so big her pussy has to stretch a little to accomidate it. Kelsey throws the shrink ray to the side and begins to bounce up and down on your dick. Her boobs bounce steadily as she thrusts and you begin  to get caught up in the moment, you put your hands on her hips and slowly move them around to her butt, you squeeze her ass as she smile and starts to thrust harder.

"Ohh yeah." she moans she bends over and brings her face close to yours and sticks her tongue out, you open your mouth and she fills it up with only half her tongue, you suck on her tongue and start to thrust with her. She lets out a gasp of pleasure as she leans forward more so her boobs are in your face, she puts her hand under her right breast and puts it into your mouth your mouth is filled with her tit as you lick her nipple with your tonguge and suck at the same time.

"OOOH!" she moans louder this time, you both are about to orgasm when you see Kylie stand up behind Kelsey, only now she is as tall as her she must have used the growth ray while Kelsey was caught up in the moment. She grabs Kelsey by the shoulders and yanks her off of you.

"No!! Kylie what the fuck i was having fun!'' Kelsey yells in anger.

"Well I was to until you came and ruined it!" Kylie yells, she throws Kelsey into the wall behind her breaking her through it into the next room, she appears to be knocked out.

"Know to finish what I started." she smiles at you and wraps her hands around your ass and thrusts you upward, your dick smashes into her cunt and she begins to thrust you up and down.

"Oooh Kelsey's got good taste when it comes to size." she says giggling and gasping. She pulls you out and sets you down on the floor. She then sits down and leans on her bed and spreads her legs.

"Well come get me big boy." She says seductivley, you put your hands on her shoulders, wrap your legs around her lower back and shove your cock back into her pussy. She gasps in pleasure as you start to thrust faster and faster.

"Yes ohh yeah!'' She moans at the top of her lungs. You cum in her and your cock returns to its original size.

"What the hell? You say. Kylie still wants more so you stand up and walk towards it, as you reach down to pick it up, Kelsey's huge hand grabs yours and she tosses you aside.

"Oh no the only one your gonna fuck is me!" she yells, she points the ray at herself.

"You mean me." Kylie shouts as she jumps up to get the ray.