The impression I've gotten from most of those steamroom guys is they just wall it off in their brain and forget about it the second they put their towel back on. They don't even talk. And if they have a wife who didn't care for sex, which anecdotally seems to happen a lot after kids, they probably don't even view it as cheating so much as scratching an itch. I'm not saying it's not cheating, I'm saying how they likely view it.