Children been called names by their father

Hi, i am after some advice. I separated from my husband 18 months ago. We went through 6 months of counselling etc to try and sort things out. One of which was name calling to the kids mainly my eldest. It had stopped for a few months but lately ive heard him start with "stop being such a cry baby" or "if you dont stop that ill ram this up your backside". I am at a loss as to what to do now