I'm on my second marriage. Was married for 20 years the first time, which was a lesson in endurance. We were married right out of high-school......probably our biggest mistake. When the marriage was winding down we had a few heart-to-heart talks, sort of a last gasp to try and work things out, but it was over and we both knew it.
Right about then an old friend of mine came to me and told me that a year or so after we were married he had seen my wife riding around with her old high-school boyfriend (who she had been fucking regularly all through high-school). He saw her twice, in fact. She saw my friend one of those times and tried to duck down in the seat to keep from being seen. Knowing her and knowing the old boyfriend, and the relationship they had in high-school, I'm about 99% certain she must've kept on fucking him for a while after we were married.
Armed with this knowledge, I cornered her during one of those last heart-to-hearts and asked her if she'd ever screwed around on me. She fessed up, and........told me about a whole different cheat that I had no knowledge of!!
Those discussions were fraught with all sorts of emotion, but this revelation turned me on a little bit, in spite of everything. We divorced soon afterward, and I got married again a couple of years later. My current, last, and wonderful wife is also an occasional hotwife.