Ty thought a fun place to start with this power would be to be born in a different country. Like a lot of American nerds, he had a big fascination with Japan, but given how far away and expensive to get to it was, not to mention the massive language barrier, he had never had any chance of going and enjoying it to the fullest. Thinking about it, he realized it would be really cool to be born to a Japanese family and live really close to the biggest nerdy centers of Tokyo.
Once he wished to be born to a Japanese couple, the ovum that was Ty changed its genes a little, and shifted from being in their original mother's body to being inside Aoki Tanaka, a 29-year-old businesswoman who had decided she wanted to mark her shift from her 20s to her 30s by becoming a mother. Her husband Chikao, a 26-year-old factory worker, had taken some convincing, but now they'd married he had come around to the idea (particularly as Aoki was now a lot more happy about raw sex).
Ty felt something weird as he saw, in his mind's eye, this couple making out and undressing: it was like he felt their arousal vicariously. When Aoki pulled off her husband's underwear and stroked his hard cock, he felt the racing of their hearts, and when Chiako removed Aoki's bra and sucked on her boob, Aoki's pleasure and Chiako's arousal flowed through him too.
When the two of them moved on from foreplay to sex, Ty felt an intense primal excitement. This couple were practically aching with fertility, racing towards their orgasms as Chiako's cock pounded Aoki's pussy and she clung to her lover's shaft every time he thrust into her forcibly. Ty even felt when the two of them held hands shakily and Chiako played with Aoki's nipples. As they grew closer and closer to their peaks, the closer he came to being fertilized, and instead of feelings of sexual arousal for the male or female body, at this stage of existence it was the act of fertilization that would give him pleasure.
Finally, Chiako grunted and Aoki moaned with pleasure as their feelings peaked. His cock painted her womb with his seed and she gripped his manhood in her passage to make it impossible for him to pull out. After a few kisses and shared declarations of love, the two cuddled up comfortably to sleep.
Inside Aoki's body, of course, things were just beginning to get interesting for Ty. As far as what sort of sperm fertilized them, they decided to...