Can you and him come up with a Code word... Something you can agree on that you can use when he gets outta hand and needs a reality check when hes not thinking clearly...

My husband and I had trouble my his boys and my daughter getting along. They came up with the word "splat" when someone used that word that meant they all had to walk away and talk about it later... they were age 10-15.. Didnt stop all the bullshyt but was helpful.