The same thing happened to my dear friend about 10 years ago; 20 some years of marriage, 2 kids and he tells her he is gay. He has known since he was 12 years old. He was surprised she wanted a divorce and his mother begged her to stay married to him and look the other way.
That is crazy. I can't understand why he was surprised she wanted a divorce. I mean, come on - you don't want to be with me. Her mother is pretty nuts too. My mom was totally "Kick him to the curb!".