Hello.. your ex may be simply holding onto bitterness about the breakup from years ago. He probably has a great deal of repressed anger issues and could have benefitted from continued mediation. It does not matter if he has another partner in his life or not. He will still "bad mouth" you. He wants to try and control you. He hopes that by "bad mouthing" you, it will push your buttons and cause you to have negative reactions. You have to be the stronger person and continue to act in the most positive way possible. You cannot change your ex. You can only change your reactions to him. Also, you might want to seek therapy for your daughter as she is being put in the middle of this sitaution and it is not her fault.