needing advice

My ex and I broke up four months ago. We very semedly stay in contact but when we do it's either him asking me to come over and hang out and watch or movie or go on a "date" I hung out with him once or twice since our breakup and when I did it was like it always was. I know this isn't healthy and an ex shouldn't have the ability to sleep with his ex or make comments such as "I wanna give you my babies" and still tell me he loves me and kisses on me when we were hanging out after the breakup.  I've never spent anytime with an ex before and for some reason don't wanna tell him no even though I have been lately. I just wish we could work on things. What do I do!?