I don't know, the whole idea of open marriage will only make your woman grow resentful on you, sit on other men and still get the "provider" privilege on you or both of these. Sure, you may find yourself getting more women and being overall more "successful" than her, but isn't this competition (even if subconscious) a proof that the relationship itself has failed?
I don't know, man. I couldn't sleep on the same bed with my supposedly wife who just took someone else's **** few hours before laying with me.