I have a 16 year old and a 14 year old daughter with my 35 year old ex-husband. We have been divorced for about 4 years now. He recently has been dating a 21 year old and she keeps "showing up" when he has visitation with my daughters. They are not married and she does not live with him. I believe it to be an inappropriate relationship and conduct for my ex to have this person around my children when he is supposed to be spending time with them.