My wife and I have agreed that neither of us wants to hear about it if the other cheats, unless we want the marriage to end. We were in our 30s when we met, and both of us have had enough experience to understand that shit happens.
I want her to be satisfied. If she needs something that I can't or won't give, shess freefto get it elsewhere. Of course, I'd be hurt if I knew she fucked somebody else, so I don't want to hear about it. And, our understanding is that if you cheat and feel guilty about it, that's your problem. We're not allowed to unburden our own conscience by putting that shit on the other person.
This works in theory. Hopefully, it works in practice too. I guess if it does, I'll never know.
That's more or less how I see it as well. Although I haven't had an agreement or anything like that with her, if I ever found out about anything there is a good chance I would leave. There is an old saying where I am from: Eyes that don't see, heart that doesn't feel. Basically it means that as long as you don't know about it then its like it doesnt exist/never happened. We have been together for more than a decade now, so maybe it does work.