I disagree. I think that if a women opens up her relationship to a 3some, I think that a man is less likely to cheat. I think if you do a survey, most men will tell you that they wont cheat in that situation.
Men cheat for different reasons. Some men will cheat no matter what under any condition. That is just the nature of the beast. However the men who maybe on the fence, and if a women satisfy that need by including someone else in the bed room, I dont think that most men will still go out a and cheat in those circumstances.
And if a man does cheat in that situation, then he obviously dont want to be with that woman.