sorry but don't see it nice. He should be saying what he did but make his mom kick the dad out. The dad doesn't need to live there. It shows that his properties are playing things on their own. I am sure both parents got the money for the properties. The dad can be around to visit the kids but don't see it nice what he did. Cheating is cheating. He said it himself if this was him. he would have kicked the maid, in his case his wife, and the husband, in his case the butler.
Once again it comes down to make women accept the situation. If the father doesn't want to leave then the mother could leave. This is just a selfish desire to keep everything as normal so he could have a "normal" life and by pushing and punishing the mother to continue showing feelings for the cheating husband. In a normal situation, she wouldn't be looking all innocent at the husband again ...especially when the maid is right next to her/them.