It sounds like your husband has a lot of faith in your relationship! I understand that it would be hard to respond the same way if the tables were turned though. We all have different levels of tolerance, there’s nothing wrong with that.
I’m probably more similar to you, though I am Polyamorous so cheating isn’t the same. If anything, there might be misunderstandings about nuance, but if someone went behind my back intentionally to hide something from me I’d be very hurt and question the strength of our foundation.