For a few moments, you stare at the handsome man your girlfriend has turned into. She- or rather he- was right, this room was amazing. And you want to try it really badly. "Babe?" you say.
"Yeah?" he replies.
"I wanna try," you smile, walking to the mirror and stripping off just like your girlfriend did. Once you're naked in front of the mirror, you close your eyes and focus on the idea of becoming a woman.
A moment later, you open them and feel an intense tingling sensation run through you as your sex starts to change. Your short hair flows downwards until it reaches partway down your back. Your facial features soften and the bulge of your larynx vanishes from your throat, your voice increasing in pitch as a result. Your body contorts, its muscles turning lither and more petite as you shrink a few inches and your proportions invert, your shoulders shifting inwards and your hips spreading outwards. Your skin softens and much of your body hair recedes away, making it smoother. Your nipples get pert and swell up, and you pant softly as breasts form on your chest. You look down to see your penis start to recede away, and feel your testicles move up inside you and reshape themselves. Soon your penis tucks up into a tiny clitoris, and your scrotum splits itself open into a vagina.
After a few moments to come down from the sensations, you breathe, "Wow, I'm... I'm really a girl now!" Your voice still sounds so foreign, clearly you but also not you.
"Yeah," your boyfriend agrees. "A really hot girl, too!" Seeing him stood naked behind you, his penis hard and erect between his legs, makes your transformed body respond intensely. Your nipples and clitoris feel hard, and vaginal juices pool around your lower lips. Even though you've never felt attraction to men before, you can't help but fantasize about him. You want him to kiss you... to touch you... to be inside you...
He comes up in front of you, a cute smile on his face, and says, "Babe, do you wanna fuck?" You nod, and feel him push you carefully to the bed. He climbs atop you and you spread your legs for him, your heart racing as you feel his hardness touch your stomach tantalisingly, slowly moving downwards.
When it presses against your pussy and eases inside you, you moan hard and he groans in surprise at the sensation. Slowly more of him fills you, and his hands carefully hold yours as he moves into you. It's so different having sex like this, taking rather than giving, having someone fuck you rather than fucking someone.
Soon his masculine instincts take charge and he's pounding into you vigorously, and it feels intense, particularly when his hands release yours and move to your chest. Having him feel you up, and his cock fill you up, it's like your body constantly telling you: you are not male anymore, you are female now. It's so different and so nice, you find yourself moaning and panting while he grunts and groans, your sounds instinctual and desperate.
In almost perfect sync, you both hit your peaks, and he pumps load after load of warm seed into you, your passage clenching and nipples and clit pulsing. As the high slowly subsides, you smile at each other and kiss, amazed how sex feels to the opposite sex.