My "relationship" is kind of bad. We have this on off thing, but when we're off, we still have sex. It's hard knowing that one minute he may be mine, and the next he may not be. I've tried talking to him about it several times because I feel used, but all I get is "come on, baby, don't be like that. You know I love you.", and I always forgive him or run back to him. I care a lot about him, but this on/off thing is driving me crazy. He's so confusing. What do I do?