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.

As soon as your fingers close around the toy gun, it lets out a shrill beep and you feel your whole body shrink down until you're no taller than an inch! You stand there, gawking down at Mayuki, who triumphantly grins back up at you. "Haha, now I get to play with my teeny-tiny stepbro!" She picks you up between her fingers and starts trailing them over your shrunken form. It tickles unbearably but somehow feels even better! "And where do you think I'm gonna put you first?" she taunts, her eyes sparkling with mischief.

Her eyes widen in surprise as you use the toy gun on yourself, making your member grow to a size that would fit perfectly between her breasts. She giggles softly and cups it there with one hand, feeling its weight and heat against her palm. "Ohh, big boy," she teases, leaning down to run her tongue along the length of your shaft. "I guess I have no choice but to let you play too." With that, she picks you up with a single finger and holds you at eye level. "But remember," she warns with a wink, "it's my turn now."

"Hmmm..." Mayuki hums in pleasure as she feels the sensation of your tongue lapping at her nub. Her eyes roll back in ecstasy and a soft moan escapes her lips. With every stroke, it gets more difficult for her to focus, but she knows you're enjoying yourself too much. "Maybe... we can... share?" She pants out between words, arching her back as your tongue continues its teasing dance across her body.

As your tongue continues to tease and stroke her delicate folds, Mayuki's moans become louder and more frequent. Her hips buck and writhe against the sensation, seeking out more pleasure from your expert touch. "Oh god, stepbro," she gasps, feeling a wave of ecstasy wash over her as you tongue-fuck her like no one else has before. She bites down on her lip, trying to stay quiet but failing miserably as the pleasure intensifies, coursing through every fiber of her being. Her nails dig into your shoulders, leaving pale imprints in your skin as she arches her back and begs for more of your skilled attention.

The pleasure washes over her in waves as you assault her with your tongue and hands, driving her closer and closer to the edge of ecstasy. Her body tenses and trembles under the onslaught, every muscle coiling tight as she nears the brink of orgasm. She moans and writhes beneath you, desperate for release but wanting this feeling to last forever. "Yes... yes..." she gasps, arching her back off the bed as a shudder runs through her frame. Her nails scrape against your shoulders, drawing blood in her effort to keep herself grounded while her entire being is torn apart by pleasure. The walls of her core clench tight around your tongue and fingers, squeezing out pleasurable moans that only serve to heighten the intensity of their passionate exchange. "God... stepbro..." she whispers, her voice barely audible over the

"Hah, not bad... but you still need some practice." She laughs and climbs on top of you, straddling your chest with her knees spread wide. "But I guess if it's good enough for me..." Her voice trails off as she leans down, positioning your cock at the entrance to her waiting wetness. With a sharp inhale, she sinks down onto you, taking you deep inside herself. Her body trembles as she feels the full length of you stretching and filling her up, but it only serves to heighten her arousal further. Her hips grind against yours, moving in small circles as she begins a slow, tantalizing ride atop your cock. "Mmm," she moans, closing her eyes as pleasure washes over her. "I think we can share... for now."

Her eyes fly open as you begin thrusting harder, making her lose balance for a moment before she grips your shoulders tightly, using them to steady herself. The sensation of being so thoroughly claimed and possess by you sends a shiver down her spine; it's almost painful how good it feels. She moans loudly, arching her back as the pleasure builds inside her, threatening to break free in a powerful orgasm. "Oh god... stepbro..." she whispers, her voice hoarse from the desire coursing through her veins. Her hips begin to move in time with yours, meeting each thrust with equal fervor as they race towards their shared climax. "I'm gonna cum..." she pants out, unable to contain herself any longer as the pleasure builds and builds inside her tight core.