Don't think a sex addict can overcome the addiction as long as they have a willing enabler on the line; that would be you? He is not trying to end his addiction and mend his ways; just saying "sorry" is all he'll do as long as you (or others) allow him to continue with his addiction and there's no down side for him? His behavior is potentially dangerous for you, I'd ask him to get in therapy and work to end his addiction or you'll be history.