Just tell yourself that going to see him will not help, because it almost certainly won't. He will see it as pressure from you.

You cannot convince or force him to give her up. All you can do is set boundaries and hold to them.

Marriages do not work with a third person in them.

M: A really long time.
Crisis: 5 years.
She's still worth it.

Life is never made unbearable by circumstances, but only by lack of meaning and purpose. -Viktor Frankl