So my FWB turned bestie has a gf of about 5 months. He told me in the beginning of their relationship that he told her about me. He sent me a text this morning that said she's going to ask me to hang out. My heart sank at first, but I can suck it up. We have several mutual friends so at least we'll have something to talk about. I just said "sure whenever I can find time to hang out". She knows we've slept together. I have no reason to disregard her. She hasn't done anything wrong to me. He sent me a text this afternoon and said "that's nice she wants to get to know you". How would you handle this?