I don't believe I've posted to you before, but I do read nearly all of the MLC threads.
Like you, I recognized many signs of an OW for some time. I questioned H about them, he always had an explanation, and I let it go. There eventually came a time, though, that living a lie became more painful for me than living the truth, whatever that turned out to be. I was losing respect for myself. I was beginning to question why I would put up with the obvious lying and cheating, the disrespect of me and our marriage, and the periodic abusive spewage. So when I had the chance, I verified and confronted. My H left the next day, and has not returned. I do not regret it. I had to stand up for myself. For me, the pain of living a lie was greater than the pain of living alone.
Only you can decide what to do here. Just be certain that you are prepared to accept whatever the outcome might be.
M 65 H 64 T 39 & M 36 @ S 12/08 Two Ds
Do you know that the harder thing to do and the right thing to do are usually the same thing? Nothing that has meaning is easy. ~ The Weather Man