I also don't believe she is in an active A. I'm there, I can read her tone and body language. I don't think she's lying. Any A that's going on is completely in her head.
Again, you are in denial. You are in an open M (emotionally), whether you admit it or not. She has kept his OM very active as the third person in this M for a long time......even if it has not been physical (which I don't what kind of proof you have that it wasn't).
You refer to a PA as being an "active" A. Maybe that's b/c men usually have a bigger problem with knowing the W is physical with another man, and if it's only in her head then it's not as serious. I don't how to stress to you that for women it is all about the emotional side of it. It is very serious to your W. It's as if her mind is preparing her body for OM, and soon as they can plan a meeting time & place, she'll be ready for the physical union. She thinks she's in love with that man! She fantasizes about him all the time (which includes a lot of fantasizing about him having sex with her). It is serious enough that it has been in the middle of this M.
If the fact that she's not in a PA is keeping you around, does that mean once you discover it has gone physical it will be the deal breaker? B/c you have repeated this same rationale several times since you first started posting, and I wonder if you would really want to know, or if you find solace in telling yourself that the A is in her head.
BTW, about those birth control pills. At first you said she told you it was for infection. The second time you said it was to regulate her periods. Did you ever learn for sure which it was?
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!