I had no idea at that time that she had been having an affair for about a month by then. What I thought was her getting back to who she was when we were dating (which was 20 years prior to this) was my yearning for the idealization phase again.
I've always been good at spotting liars, phonies and hypocrites and in work situations I knew how to handle them. But with my BPD (w/NPD traits)xbf all those qualities left me and they were replaced with one giant sign saying "I WANT TO BELIEVE". Only when he got me angry enough to hack his mail I found out he had been cheating two years earlier. When I had the facts in black and white I got some sense back. He probably cheated more often but I'm glad I don't have evidence. I think I would still find it difficult to handle that. Maybe it was those times that he was in a really good mood and I was thinking things were going great between us. He might have been feeling superior because he was fooling me and I didn't have a clue.