It's hard for me to believe this is the case for everyone. But I've never been the married one in an affair. Having been in what I thought was an exclusive relationship and my partner cheated, I didn't want to know the details. I made a decision to stay, for a while, but eventually left for a variety of reasons, not just the cheating. Mostly because the cheating showed me such disrespect. I didn't want to know the details of his sexual activities with someone else. I just didn't want to know. But perhaps I'm different than most? I don't know.