My husband and I are separated because he continues to maintain contact with her. I do not believe he is involved in active affair behavior with her. He has also maintained from the beginning that he doesn't love her and I know in my heart that he doesn't. Why he stays involved with her is a mystery to me but I suspect it has more to do with his fear that too much has happened for him and I to reconcile, than it does with there being anything particularly special about her. Her best quality in his eyes, as far as I can tell, is that she liked him, made him feel appreciated, and that she represented distraction from the things he was unhappy about in his real life. And because she has apparently professed love to him, and divorced her husband faster than I even thought was possible, I'm not willing to tolerate any contact between them, regardless of how limited. So, we remain separated. He is still very present in our lives, however, and I'm trying to get to the point where I'm capable of talking to him about what happened without dissolving into overwhelming anger and hurt. Until then, I try to keep conversation limited to business of life and to keep those interactions as positive as possible.
I am pretty sure that is where my husband is but he stays with his OW whenever he is close to her. So pretty much every Sunday night. We are not sepearted but kind of are due to his weekly travel schedule. He's home Friday and leaves Sunday but he sleeps in my son's room. I hardly talk to him anymore. Doing the 180 right now and it's hard on him. He actually talked to me a little yesterday no yelling and I told him, we would be okay with out him. I also know he doesn't love her it's the exact same thing you said "Her best quality in his eyes, as far as I can tell, is that she liked him, made him feel appreciated, and that she represented distraction from the things he was unhappy about in his real life. And because she has apparently professed love to him" because that is what he said about her making him feel joy and appreciated and the sex. It's so frusterating but I guess it's life.