MLC's main ingredient is depression. Depression runs throughout the crisis and eventually it may get a bit worse and he will go into withdrawal from you, children, pets, friends, etc. Keep in mind that the stages are not linear, but he can bounce back and forth from denial, anger, replay and withdrawal throughout the crisis.
The "stages" are the same whether he's in an affair or not. He will find something else to take his mind off the real reason he's feeling the way he does. The OP is nothing more than a distraction/band aid to his issues. Some become workaholics, sports addicts, working out at the gym, take up sailing, traveling, alcohol, drugs, porn, etc. Anything that they think will ease their pain and eventually that new activity will not "fix" that pain and he'll try something else. This cycle will continue until he finally faces his demons, accept that he wasn't responsible for all that may have happened in his young life when he was stunted emotionally.
I am going to suggest that you read HaWho's threads. Her h is still home and is still acting like a teenager/early 20's and I do not think the man has anything going on w/OP.
I also suggest that you go back and re-read the homework assignments you were given when you first came here. Also, take some time to read the threads of other posters. You'll learn so much from their postings. You can't fix and/or control him. The only person you can control is yourself and how you react to his behavior. You didn't break him, therefore, you can't fix him.
Take the time to read the threads, come back and ask questions and don't be a stranger. We are here to help you.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.