Making it so ex can only contact in regards to child

My fiance’s ex has a tendency of texting and calling him whenever she likes to make jabs about him as a person and father. She demands info on our personal life, talks trash about my children (which she better stop cause Idont play!) Yells at my fiance, and constantly refers to anything good that happens for us as dirty laundry. She also uses their child as a bargaining tool, saying if my fiance won’t tell her what she wants to know he won’t get to see the child and that’s how it is because she’s going to do it her way and that’s it. She is manipulating and trying to control his life and to a degree mine too. Its not fair. Neither of us have any sort of contact with her unless its about the child and then we say what we need or get info and end the convo. Is there any way it can be written up she does not contact us unless its about the child, only the child, and she has to be civil about it?

If there is not a child custody order in place, you should have your fiancée file a claim and have a set schedule put in place and request the court put parameters around communication.