I totally agree with other posters, you have to get out for your children's and your safety. This man does not deserve a second, third etc chance just because he has issues. Assaulting a child or adult is totally unacceptable.

Am no expert on potty training, but listening to others' experiences there are no set times and can even have "accidents" when seven years old. Some boys can take longer to be dry than girls. Anxiety of upsetting his father isn't helping your son be successful. Even children of their ages pick up on these things.