Where does he live? Does he have his own place? He could just be going over to see his daughter and the daughter could be trying to instigate things hoping her parents work it out . My parents got divorced when I was 5 and I always hoped they would get back together and when my parents started dating other people I would get upset and try to break it up.....I bet it's the jealous daughter causing trouble but keep your eyes open for any clues that something may be going on...