Firstly, you both have my sympathy. Your daughter is in a very difficult and unfair position she should not be in. As she is old enough to do so, I think she should tell him that they need to set a new rule. She will not come to see him any more if he talks about or asks about you. After all, her visits should be about her and her father's relationship, not about anything that pertains to you. If however, when she visits him, he does not stick to this rule, then she should tell him that he has broken their new rule and that she is going home because of it. She must be consequent though and follow through by leaving. He may learn his lesson after the first time or (if she wants to try again) he may need to experience her strength of character more than once. He needs to learn to respect his daughter and to understand that she will not allow herself to be hurt in this way. It is important though that she tells him that in all honesty, unless he stops asking and commenting about you, he will lose his daughter. It is her he should be interested in , not her mother!!! I wish you all well with this.