...an improved version of yourself." You answer as she checks around.
"Did it work? I don't feel anything," your girlfriend asks as she's waiting.
"I think it's loading. But don't worry. It'll work. Don't let the bodysuit fool you. It may look like a tight but stretchable piece of fabric, but it has special properties, I tell ya, babe."
"I think you just want to see me in a tight suit, that's all." Your girlfriend teases you.
"Maybe..." You glance away
"You're such a dork! Fine, I'll please my boyfriend here." Your girlfriend nudges you and giggles. "And I think it's probably not working while you speak. Let's try to er... Oh! I got it. How about commanding the suit instead and seeing what happens."
"Okay, I'll try." You say as you try to command the suit. "Let's see. Command: Transform Into 10-year-old boy."
As you're commanding the suit to transform your girlfriend, she then stood still and froze as the suit began to change. First, the bodysuit started to disappear on her skin, as it was merging with her, and now you can see her entire naked body, and your girlfriend seems to be younger as she started to de-age. While she shrink a few inches shorter than her original 5'2" height, her hair was getting shorter too. Her hair, which was shoulder length and light blonde, has now turned brown and shortened to a boyish pixie hair. While this keeps going, you start to notice her breasts, which decrease from a nice C cup to a flat chest. Of course, you gotta miss those as your girlfriend is going to become a boy for a while. Along with her deflated chest, her skin seems to get a bit lighter, smoother, and tighter. Her vagina starts to form a little boy's penis that fits at the age of 10. Finally, her face and voice both seem to contort and reform to more boyish tone and less feminine to resemble a random boy.
Finally, when the transformation was complete, standing before you now was no longer your girlfriend anymore, but a naked cute 10-year-old boy was standing there.
She... rather, now he blinked a couple of times as he finally moved. S/he then...