Hi! I think your partner needs to make a decision on which person he would like to be with. It isn't fair of him to have his cake and eat it too. It's like wanting to have the best of both worlds. When my husband does stuff like that, I make him decide on one. Tell him he needs to figure out who means more to him and who would he rather be with. In the meantime, hope for the best and prepare for the worst. Good luck to you!
