My first marriage ended in the late 90s during the golden age of internet dating, when everything was free, even Adult Friend Finder and the like. I (and later I and my girlfriend) spent about two years fucking dozens of women in various combinations until I literally got bored with that lifestyle. I did not married again until that was all out of my system, and honestly haven't been tempted in the 10 years I've been married the second time. I told my wife up front that if I run into a situation with twin 16 year old cheerleaders on an airplane, all bets are off, but apart from that, there's nothing out there I want to do that I havent' done.
Of course, I realized later that I may have unduly limited myself. If the twins are 17, or drill team members or it's on a bus or submarine, I don't think that's covered by the exception.
I would have gotten away with it too, if it weren't for those meddling kids!