As Emilio's handsome, masculine body pressed against her beautiful feminine one, Ty came to a realization. Eileen had mothered a child as a woman, but Emilio hadn't fathered a child as a man- even though he could. And his- her- body would be perfect for it.
"Would my girlfriend be OK with me fucking her?" asked Emilio.
"Please do," Ty replied. Emilio was about to sit up to get a condom, but Ty gripped his arm and said, "I want to do it raw."
Emilio looked concerned for a moment. "But what if you-"
"-get pregnant?" Ty finished. "I want to."
Emilio knew rationally he should tell her to have some sense and use protection. But his still newly masculinized mind was transfixed by the possibility. He could get her pregnant? She'd like him to? Any rational knowledge that that wasn't a good idea was swept aside. He slid his cock over her moist pussy lips, hearing her breathing hitch, and then slid inside her fresh vaginal slit.
Ty heard herself whimper and then moan as she was penetrated, and it felt like Emilio was castrating her all over again. Every sensation- the stretch of her passage to accommodate him, the firm flesh of his cock filling her, the weight of his body pressing atop hers- reminded her that he was a man, she was a woman and this was how sex played out in their reversed bodies.
At first it was pretty overwhelming, but to her relief Emilio sat up, giving her a good view of his toned upper body, and reached down to cup her breasts. She moaned in surprise and Emilio grinned. "You've got really soft, big tits, you know that?" he remarked.
"Th-thanks," Ty gasped, her voice hitching thanks to Emilio's firm, dark hands playing with her soft tits. She felt like she could melt with pleasure under his touch.
After a few moments, Emilio asked, "Is it OK if I move?" Y-you're really warm and tight."
"O-OK," Ty breathed, and as Emilio's cock pulled back until only his head was inside her and then slammed back in so hard and fast his balls slapped her flesh, before he set about repeating this motion faster and faster, she lost the ability to speak coherently. She whimpered and moaned in ecstasy as his shaft rubbed along the sweet spots deep inside her, and his shaky fingers gripped her chest and pinched her nipples.
Before long both their orgasms drew near, and their minds were drawn back to what they knew would result from this. "Ty... I'm... gonna cum..." Emilio groaned, and as he spoke Ty saw in her mind's eye the chain reaction taking place inside her.
She saw Emilio's cock splurt thick cum inside her as he peaked, and the sensation of his manhood throbbing made her cum. Her orgasm was accompanied by her cervix dilating to allow as much of his semen inside as possible. By now even if they hadn't consciously desired this, their bodies' instincts made it inevitable anyway.
Emilio's freshly spawned sperm raced through the passages of the girl they had been shot inside, as virile as if he'd been a man forever. Deep inside Ty, her body's newformed ovaries had released an ovum, as nubile as if she'd been a woman forever. They sensed each other, and their convergence was unavoidable.
Sure enough, the innumerable seed soon reached the egg and set about chewing away at its walls, each tiny cell desperate to fertilize it. After much effort, one pushed inside and the zygote moved into Ty's womb to settle and grow.
Ty's focus returned to the impressive man gasping for air atop her, as she realized he had just made her pregnant.