...if you caught your significant other about to cheat, but the fact that you caught him stopped him from doing it. Otherwise, he would have gone ahead with it. This just happened to a friend of mine and she is leaving her boyfriend because of it - in this case, "about to cheat" and actually cheating are the same thing to her. She is packing her things and leaving him.
Would you leave your BF/FI/DH? What factors would you consider when making your decision?