I have been playing around with this girl I work with, she asked me to have sex. For whatever reasons I rejected her. Now she has a boyfriend. She started playing around with me today, and said want to me my baby's daddy? I kind of thought it was a joke, but I mostly thought she was serious. I later told a friend, he said it was a joke. I don't believe him, I really don't know. Now, I am interested in having sex with her, what should I do?