Any stories or experiences where the other man thinks the wife/gf is cheating on her man?

I love stories and experiences like this, the hotwife goes and sleeps with someone who thinks she is cheating on her man, but in reality the husband knows everything.

I find it really hot - the other guy getting his ego stroked thinking that he’s nailing a cheating wife, and the interactions between the husband and the guy afterwards who has no idea he knows about it.

Any stories?