He tells them they can stop being rude to his wife and be included in his new life or they can keep being wenches and he can cut them off. Then he sticks by what he says.
He definitely needs to stick up for you and your relationship!
I third this.
And when this began, he should have spoken up and told them to cut it out and not to do it again.
Again, this is an H problem, not an in law problem. Pity. You married a candyapple, not a man.