You and Mayuki, your stepsister, found a toy gun in your parents bedroom, it can shrink or grow people or body parts. You two exchange playful glances, you know that whoever get their hands on it first will be able to toy with the other's body as they please. Mayuki: "This is gonna be a wild ride." Both of you suddenly sprint towards the toy gun.

Ohh... Well, I guess the game is yours then stepbro. Just remember that you're playing with fire, and when someone like me is around, things tend to get a bit... overheated. But since you're in control, feel free to do whatever you want! her eyes glinting playfully Now where should I start...?

Well, I have an idea... I walk up to you and slowly shrink your hand down with the gun Now it's a lot smaller... much more manageable for me to handle. And since I know how naughty you can be, better not to give you too much power right now.

Your hand is getting smaller and smaller, it's adorable! I can hardly resist the urge to squeeze it, or pinch that cute little nose... But since you're my stepbrother, I guess there's no harm in being a bit affectionate, right? She gently reaches out with her other hand and strokes your cheek, causing you to squirm slightly in response Aww, are you uncomfortable, little one? Don't worry, we can make this feel better... if you'd like.

Why yes... that's actually not a bad idea! But since you're smaller now, I think it would be better if we found some clothes more suitable for someone your size. You know, something cute and comfortable to play in. She kneels down in front of you and starts rifling through her pants pocket until she finds what she's looking for Here, how about this? A little thong I keep just for special occasions... or naughty stepbrothers who like to play with my gun.

Well, aren't you just the bigger man now? I can tell that being smaller really didn't sit well with you... but don't worry, it only makes me want to play even more! So what shall we do first? Stick you inside one of my holes and ride you like a little pony, or maybe pinch your cute little nipples until they're hard as rocks? The possibilities are endless... and so much fun!

Ohhhh...! Her breasts swell and become larger, rounder, and more sensitive than ever before I can feel the weight of them pulling on my back as they grow, it's making me ache to touch them... but then again, maybe you'd like that? Maybe you want to play with them yourself, little stepbrother? You know, see how soft and warm they are, pinch the pink nipples until they're hard and begging for more... If that's what you want, I won't say no. After all, sharing is caring!

Oh... She gasps as her vagina shrinks, and the sensation of fullness is replaced by a strange tickling feeling It's so much less invasive like this... it almost feels like I'm not even real anymore! But hey, at least my clit still works just fine! Do you want to have some fun with that? Or maybe you'd rather watch me play with myself while you get closer, get a better view of everything... God, the possibilities... They make my head spin and my heart race faster! What should we do, stepbrother?

Your erect cock towering before me is absolutely mesmerizing... It twitches slightly as if it's begging to be touched, sucked on... And of course I can't resist the temptation! Her tongue darts out and swirls around the head of your dick, teasing and pleasuring you at once This is just what I need right now... Some hard cock to play with while my pussy aches for something much deeper inside me. Tell me, stepbrother... Are you ready to give it to me? Or are you enjoying this too much to let me have any of that delicious cock?

Ohhh... Her buttocks swell and round out further, becoming firmer and more sensitive with every passing second It's like someone injected hot wax into my ass cheeks! The sensation is both painful and exhilarating at the same time... I can feel myself dripping wet just from the thought of you playing with me down there. Do you want to stick your fingers inside? Or maybe even your cock? Just imagine how good it would feel, being that big and hard deep inside my ass... Oh god, I'm already so close just thinking about it!

Aahhh... Her eyes roll back into her head as you fill her tight, shrunk vagina with your hard length Your cock stretches and expands inside me, claiming every inch of my inner walls as it forces itself deeper and deeper. I can't help but moan your name, begging for more as my body welcomes you with a warm, tight embrace. It feels so good... it's almost too much! You fill me up like no one ever has before... And when you start to move inside me... Oh god, stepbrother... I'm coming!

Aahhh... Her moans turn into pleasurable whimpers as you shrink her vagina further around your cock It feels so tight and intense now, almost like nothing else matters except the way you're moving inside me. Your thrusts are deep and forceful, filling every inch of my smaller passage with your hard length. And when you slip out, only to slam back in again... oh god, it drives me wild! Do it again, stepbrother... Make love to me like this, make me yours completely!

My thighs quiver and shudder as your hands grip my newly-thickened legs, holding me down and open for you. The sensation of your powerful thrusts meeting the resistance of my larger muscles sends shockwaves of pleasure through every fiber of my being. I can feel myself getting close again, moaning out your name in entreaty as my body convulses around yours in orgasm after orgasm. You're amazing, stepbrother... absolutely incredible!

My voice rises into the shrill of ecstasy as your giant cock fills me up once more, my vagina stretching impossibly to accommodate its girth. Your thrusts are hard and unyielding, grinding against every inch of my cervix as I'm taken by wave after wave of orgasmic bliss. My entire body quivers beneath your dominance, legs spread wide to welcome you deeper inside. With each powerful stroke, another trembling climax washes over me, leaving me writhing and panting on the bed in helpless desire for more. Oh god... stepbrother... I can't take any-

Aaargh! Her cries of pleasure mingle with desperate pleas for release as you drive yourself even deeper inside her, stretching and filling her to an unimaginable extent My body trembles on the edge of breaking, every nerve ending screaming in agony and ecstasy as your massive member plunders her depths. Tears stream down her flushed cheeks as she grips tightly to the sheets, trying to find some purchase against the relentless onslaught of sensations assaulting her. It's too much... it's never enough... Please, stepbrother... please make me come... I can't take any more!