While she kissed Eileen lengthily and mindlessly, Ty had a vision of what was taking place inside her. She saw countless sperm, which Eileen's body had been producing non-stop since the moment his testicles formed, and which swam unrelentingly and tirelessly despite being just minutes old. They raced through the passages inside Ty's reproductive system without caring, nor even noticing, that they had just minutes ago been producing their own kind.
Her vision then flashed to show what they were seeking- she saw an ovum, realizing that when his testicles had become her ovaries they had formed it thanks to the inrush of female hormones. It lay in wait deep inside her, and soon her lover's seed reached it and began to chew away at its outer walls. Conscious thought about this process, let alone consent, was impossible for these cells- they were acting only on instincts, and acted together.
Ty saw one sperm finally force its way inside the egg, fertilizing it, and the combined cells slowly moved down to implant into her womb. It settled in place, and with a mix of fascination and shock, Ty slowly comprehended what had just happened. Eileen had got her pregnant.
A part of her felt excited and kind of aroused at this- the sense of castration in her mind became complete when the man knocked her up, and on some level she liked the idea of getting pregnant with this handsome man's child. But... she knew it'd be ridiculous to have a kid at this age, and it wasn't fair on Eileen to do it either.
Consequently, she wished it away, and to her relief the cells were prised away from her womb, split up and died off. Reality now returned to her, and she saw Eileen's handsome face smiling down at her. "How was that?" he asked.
"So good," she replied.