Becky was worried. She felt around for her slit or any kind of opening, but found nothing. She wanted to avoid pregnancy, not turn into a barbie doll! What had they done to her?! She went into her bedroom and flung herself down on her bed in despair. That's when she felt a pleasant surprise - a warm tingle inside. Becky rubbed her crotch and the feeling increased. She felt horny, but also felt something moving inside her. She was rubbing the green ooze or whatever it was when it hit just the right spot and she orgasmed. Becky continued to experiment as her body shook with pleasure.
Later, after she had recovered, she found the literature she had been provided with. They had given her an lab-engineered organic symbiote creation. It would provide a barrier to impregnation while being fed with nutrients from her body, including when she urinated or ovulated. She was encouraged to experiment. Becky smiled at that - she had certainly done just that!