Hey Deb, Zukesters is on his way home from work now, so he can't reply.
I think he is trying to find out from his mom more about his dad, or maybe some character flaw he has always had that she may know about. His dad was an alcoholic. No indication he cheated on his mom, but alcoholics frequently do. He didn't really know his dad, so maybe he is thinking she will give some guidance to him.
Mostly, I think he realizes an apology is long overdue to her. I never told my family or friends, although I am very close to them, because I always had faith the first time around that we would work things out. So, I talked to his mom because she is his mom and I knew she would forgive him. She was my support, along with this BB, of course. He never said thank you to her for being there for me, and never said he was sorry for the pain he caused her.