Hearing Ty's question triggered something in Eileen. He felt a kind of primal, masculine satisfaction at the realization he had just got a woman pregnant, and even though rationally he knew from having been one herself just minutes ago that Ty definitely shouldn't have to keep it, his new self possessed his voice before he could suppress it and made him say something he knew, and didn't care, was wrong.
"You'd better."
Hearing the two words made Ty get butterflies in her stomach. She hadn't expected Eileen would actually want her to have his baby, and yet the prospect was so exciting to her. She noticed Eileen had gone beet red, though she didn't notice she was blushing too, and heard him add, "Sorry, Ty! I don't know why I said that, my body's just-"
Ty cut him off with a passionate kiss, and she whispered, "I want to keep it too," rubbing her body against his and preventing his erection from wilting despite having just cum.
Hearing the young woman's consent made Eileen's hesitation wither away, and his new self's instincts took over. He pushed Ty back down so they were cuddling, and whispered in her ear, "I'm glad you got bred like a good bitch."
Ty felt a shiver run through her both from Eileen's words and his dominant tone of voice. "So am I," she breathed.
"It's so strange to think you used to have one of these," Eileen laughed, gesturing to his manhood, and Ty stared in wonder at the phallus that had just inseminated her and made her pregnant. "But then you castrated yourself and became a fertile female, perfect for a well-developed male stud like me to mate."
"Yeah," Ty agreed. "Your body is so hot, I couldn't not invite you to fuck me." The emphasis on the reversal of their roles was making her so turned on she couldn't put it into words.
"Thanks, babe. I can't wait for your body to swell up with our caboclo baby," Eileen purred, the foreign word exoticizing their love further still.
The idea that anything about their situation was strange was fast fading from their minds. They simply knew they wanted Ty to bear Eileen's child.