I remember XA would blackout probably 5 out of 7 days of the week.
Sometimes, I would back pedal the previous nights events ( to him) to see where he checked out at, and many times it was much earlier than i thought . He was still walking, talking, eating, drinking, dancing, but the next day, he would ask where we went to eat? what time did we get home? who did we see? It was pure insanity.
Only you can decide what an acceptable standard of living is. Cheating is a deal breaker for me.
If I were in your shoes, I do not believe I would grant him that "get of jail free" card. Just because he was drunk, does not excuse his unacceptable choices.
Have you ever heard the saying, " sometimes we give the booze too much credit?"
Realizing your plate is currently overflowing, now may not be the best time to say this but,.......... I read quite a bit of denial in your post, " the he would never intentionally do this" is making an excuse for an ADULT MAN who is supposed to be RESPONSIBLE for himself.
You cannot own his disease, I can only hope this is his bottom, and he is seeking out IMMEDIATE help.