My ex also used our son as a weapon against me. He also would use my son's love for me against him. He is a devil.

My aggravation didn't end until my son was grown and I didn't have to have any contact with my ex.

You're in a really hard place. You seem to be doing everything you can to protect your child's relationship with his father.

Maybe it helps to think how much worse it would be if you were still married and had to see this jerk every day.