Meh, wife swapping seems to organized.
What I've always told my wife is if I ever got that overwhelming desire to sleep with other women, I would simply come to you and tell you. Then we could decide if an open marriage is the best option, or to end our relationship.
It sounds pretty brutal, but it leaves no room for cheating, and aids in a trusting relationship.
Personally I think I could easily sleep with other women and no have it effect my marriage at all. Problem is I couldn't bare the thought of my wife doing it. So in that hypocritical stance my sex life is just going to have to stay familiar.