Most Helpful Guy
Without knowing anything more, it means:
1. You are engaging in certain behaviors which cause him to be suspicious,
2. he in insecure and afraid that you are going to leave him,
3. he has a paranoid jealousy that is totally unrelated to your behavior, or
4. he is being unfaithful to you and trying to justify his behavior by accusing you of the very thing that he himself is doing.
Most Helpful Girl
He's prob trying to get under your skin. I had a friend who did the exact same thing to me. Just don't show him it gets to you.