You also say he tells you the reason he did it in the first place was because you were nagging him and the girl he found was easy going. If I were to take a really challenging position, I might ask: do you actually have a tendency to nag? I ask not to justify his actions in any way - even if what he said was true, cheating isn't an appropriate response - but because sometimes it's important to pause and think about how talk to a partner about getting our needs met. In counselling, we often see couples where one person is saying that their partner nags them all the time - but when we get right to the bottom of the problem it becomes clear that the nagging is just their way of showing the other half how unhappy they’re feeling. Not surprisingly though, when we keep saying the same thing in the same way over and over again, our partner might just switch off because all they think they hear is blame. And so - sometimes - they act out. Again, I mention this not to justify what he did, but to offer some chance of understanding it in context.