I don't think the initial having him move out was too bad to be more intimate with his wife. Probably should of called him when you had the kid though.
In the end he is still an asshole BUT Sakurai is an adult. His father is a bad person, not a bad parent. Since this is a conflict between two adults. That being said man what a dickhead.
Though a 49yr old having a child sounds life threatening. I've heard it's not translated but thats REALLY late