P.P.S. Think of it this way... You are at least in some kind of R with W that is something like dating. For your own sake, you shouldn't be dating someone that you can get clear answers to for the following questions:
1) Are we in a monogomous R, physically and emotionally? 2) Are we in an open R that allows us to see OP with whom we are involved physically or emotionally? 3) Are we in an R in which we honestly disclose our contact with OP? 4) Are we in an R in which our private lives are our own business? 5) When is the last time you had unprotected sex? 6) When is the last time you were screened for STDs? 7) When is the last time you had oral/vaginal/anal sex? 8) Are you seeing OP? 9) Are you still involved with ex-boyfriends and if so how? 10) If we are in a monogomous R (emotionally and physically), what counts as cheating in your mind? 11) If we are not in a monogomous R (emotionally and physically), what counts as lying about your involvement with others in your mind? (Many people don't count non-disclosure or even "white lies" as lying when they are in open dating Rs.) 12) Do you have children with OP or might you be pregnant?
What are your boundaries with this dating R? Determine your boundaries, and then figure how far each of you are into the dating R. It probably is not healthy for you to be more into the R than she is.