It sounds to me that you and the X are both responsible for your kids behavior on the phone. I good way to get your kid to speak properly on the phone is for you, and your X to interact on the phone with your kid. BOth of you should be teaching him phone manners. It's not just the father, and the childs fault here. It everyones fault. I believe that every NCP should have phone time with there child(ren). Here in Michigan the courts encourage phone time. They leave it up to the parents to divise a schedule. The way I see it here, both parents are at fault for your childs phone manners.