"Ty?" His eyes met Ryan as the dark-skinned boy spoke, and he saw Ryan was smirking.
"Yeah?" Ty replied.
"I want you to turn into a girl for a bit."
Ty's heart missed a beat. Seeing Ryan change like he had made him really curious about what it'd be like in his own right, but hearing the handsome young man tell her to do so made his curiosity irrepressible. "Yeah, OK!"
He looked down at himself, focused for a moment- and felt a tingling sensation surge through him. His body felt... softer. More petite. Pliable. His clothes felt weird on his skin as it smoothed, and he grinned at Eileen, "I'm gonna take these off now." He pulled his T-shirt over his head and threw it to the floor, slipped off his cargo pants and removed his boxers, allowing his hard penis to emerge. He and Ryan noticed that Ty's wasn't as large as the dark shaft in front of him, and felt a sense of anticipation at knowing that was an indication of things to come.
Speaking of coming, fuck, this felt nice for Ty! He got a euphoric fascination as he saw and felt his body reshape itself into her body. His muscles and hands and feet shrank and turned more lithe and petite, and he felt his hips and butt fill out and widen to feminine proportions. He ran his hands along his skin and noticed most of his body hair had receded, and his skin had turned smooth. Shivers ran through his face and neck as they reshaped, his lips getting noticeably puffier, cheeks softer, and voice higher, the bulge in his neck vanishing.
Ty's eyes fixed on Ryan's thick, hard phallus again as his own reproductive system set about inverting. He bit his lip as his nipples grew sensitive, the areolae widened and puffed outwards, and with each deep breath he took soft mammary flesh expanded under them. Soon Ty had developed C-cup tits, and he felt Ryan staring at them arousedly, and felt a weird proudness at turning him on.
He whimpered in a soft voice as the last, most male part of his body became female. He peered past his breasts to see how his penis shrank away inside him, and felt a clenching sensation at his crotch- followed by two wet pops that marked his castration. Inside her ovaries formed from his testicles and linked to an expanding womb that had begun to reach down to her crotch, while his scrotum shrank inwards until it became flush with his crotch and spread open into moist, vaginal lips. Meanwhile, his shaft had rapidly shrunken to a tiny sensitive nub, which formed a sensitive clitoris. As Ty's body finished reshaping, she found herself accepting that she was a girl now- the name 'Tyra' came to her.
Once she was able to focus herself enough to look up at Ryan, Tyra noticed he had a hazy, aroused grin on his face.