Usually dudes I've known, you dont know they are cheating till after they've cheated. Like they are so proud of themselves that they have to tell someone after they know they can get it again when they want..now they can brag about it.
Usually if I cared, I cared more about their lady than their knuckle head ass. I'm not gonna tell a man what to do, but I would talk up their lady. Or talk down on other ladies to get them to realize what they had.
If a mans mind is made up to cheat, you cant talk him outta it. All u can do is help him get her back when shes ready to do something about it.