Why can't I get him?

My ex and I dated for a year, but it was off and on. He always broke up with me and never really had any good reasons. It's been 4 years now and we still have the exact same feeling as before. We both have grown up a lot and things have changed, but our feelings haven't. We decided to stick to being friends, but really we never have been. The past 4 years we have hooked up here and there, but nothing official. In the summer he asked to get an apartment with me, but of course I don't have the money for that right now so I said no. I decided it was time to move on and start distancing myself from him, which it worked for a while, but later everything got all messed up again. He texted me he missed me and was thinking about me. I told him when someone misses someone they do something about it. He said, "what can I do? Promise you shit that I know isn't true, lead you on or get back together with you for a grand total of 3 months?" I said, "you have been leading me on for how long now anyways." He said, "It's the only way I know how to deal with the feelings I have for you because I know it never works out in the long run no matter what." How can he possibly know that, it's been 2 years since we last dated, I've changed a lot and so has he. Anyways later that day we talked in person and he said, "so you want to get married? Lets go out and do it." I said, "no you can get divorced just as fast as you can get married." He said, "we wouldn't." It makes no sense why would he waste his time and mine if he magically knows it's not going to work out in the long run. Especially saying lets get married, like where did that come from? It's not like I give in to him and have sex when we hookup here and there, so he's not getting anything out of it besides making out once in a while. He has no reasoning behind anything and he knows exactly how I feel about him and that I want a relationship. Thoughts on this guy?

Its been two years. Maybe it would work. Neither one of you know. He was only voicing his insecurities and his concerns when he said that stuff. He's still interested in you "you have been leading me on" you don't say that unless you have feeling to be led on. He misses you and thinks about you. He's just as scared as you are that it wont work out again. But maybe in two years you both have learned more about each other and how to make a relationship work.