If he is so unhappy why won't he move out?

My partner and I have been together for a very long time and live in my place (I am buying my place). Over the past few months everything I do is wrong from eating, walking, talking, communcating and the list goes on. I told him if he is that unhappy then move out and buy your own place ....... for a couple of days he doesn't pick on me and then it starts up again.