Realistically, Ty knew she should probably use her wish to get rid of the pregnancy, since she knew she couldn't handle having a kid. But for as long as he'd been aware of his own sexuality, Ty had had a breeding kink. As a teenage boy, he'd fantasized so much about getting to strip Eileen naked, pin her to the floor, pound his cock into her and fill her with cum so she'd conceive his child. And even though turning into a girl had altered his sexuality, she still had the same kinks- and the idea of Eileen having pushed her down, fucked her with his thick dark cock and made her pregnant turned her on just as much as his masculine fantasies always had, if not moreso.
She noticed she was getting aroused all over again- her nipples and clit were erect and her pussy was leaking juices. Not only that, her mind kept picturing Eileen atop her, and recalling how his body had felt against hers. Her hands returned to her chest and crotch, and she vividly realized her body was able to have multiple orgasms now.
Shutting her eyes, Ty saw himself as a boy again, only for Eileen to step forward, giving Ty a view of his handsome naked form. He felt his body turn to her body of its own accord, his chest sprouting into breasts, his penis and testicles tug up inside him and a vaginal slit form between her legs- his castration was accompanied with the acceptance that he didn't need to breed, she needed to have this man breed her.
Sure enough, Eileen pushed her down, mounted her and slid his cock head over Ty's clit and her pussy lips, making her gasp in anticipation. He pushed inside and pounded her with the force and desire of a male animal, making Ty moan like a bitch as she clung to him. She saw his shaft thrust in and out of her faster and more passionately, and heard him groan in satisfaction along with her pleasured moans, as the tip began to pulsate and thick white seed started splurting from the tip, which swam towards an egg inside her and fertilized it.
Ty's fantasy then collapsed into a repetitious cycle. Her belly swelled with her offspring, Eileen held her hand while she birthed it into the world, and the newborn suckled mother's milk from her breasts. Once it slept soundly, she put it to one side and Eileen pounced on her, filling her with his cock and pumping his sperm into her to make her pregnant again.
Ty felt like her mind would go blank with the endless shameless sex she pictured. Her DILF lover's thick dark cock made her conceive and bear baby after baby out of his warm, sticky semen, returning the favour by pleasuring her over and over. She loved how large their pretty, mixed brood was growing, and imagined Eileen just mating her forever, her body birthing countless offspring for him as he took full advantage of his young lover's fertility.
At last she felt herself peak, cumming hard and her nipples and clitoris throbbing against her fingers. She gasped for air, almost overwhelmed with pleasure, and wondered whether she wanted to act on the intense fantasy she'd just pictured...