Why does anyone cheat? It starts with a lack of integrity. Vows don't mean anything to those people. Their word isn't worth squat. Honor is a forgotten concept. The idea that one should be bound by their word, and honor their vows is laughed at. It's "old-fashioned", "archaic", "a silly notion from a by-gone era". Anything which causes inconvenience is to be avoided, anything which would curtail ones whims and fantasies is to be avoided, broken, or set aside. The importance of the individual is paramount! It's all about "ME! ME! ME!" Self-actualization. Self-realization. Self-agrandizement. Self-serving.
My ex-wife cheated herself right out of marriage to me, although I was the one who had to physically get up and walk out. Now she's in an abusive marriage with her current husband. I never abused her, or even raised my voice to her. As far as I'm concerned, she got what she deserved. My life is much more peaceful, calm, and fulfilling without the stress and pain of betrayal. I'll wait for the right woman to come along, a woman who takes her vows seriously and keeps them, whose word is her bond, who can be trusted even when she's not being watched. That's integrity!