I think a BS always has that question lurking...if someone had asked "What would you do if you caught your H cheating?," before the A, most of us would have said that the M would be over, yet here we are. I don't think my H will ever understand why I stayed...during the worst fog of the A, after he and OW "mutually" decided to not have contact anymore, he told me I had "won"....yea, I know...won what??? Sometimes I am not sure if that is still in his head. Other times, I think he realizes he won and dodged a bullet by not ending up more involved with her.
My youngest, a teen at the time, was a factor in me staying then...that and the fact that I really didn't see my 35 year relationship with a man I truly loved being over. In my mind, I respect me for that...it doesn't really matter what anyone else thinks.
When I asked him, what if it had been the other way around, he said he wouldn't want to know...that explains a lot.