I can understand how it can be hard to know how to respond when a friend like that is experiencing marriage problems, cheating especially is very big challenge.

You learned something from this, give this person some time. I hope this person is working with a T for support with this challenge. Give him some "space" if he needs it. It could also be that he doesn't have energy to talk to anyone right now, as I mentioned having a spouse cheat on you really hurts, I know, I experienced that myself and I was in no condition to help or really listen to anyone else either. I was deeply hurt and very lost when I experienced it. So as I mentioned, give this friend some space.

OE