My question was very unclear, and I didn't want to give away to many personal issues on him before.

Here's the low down, seeing him, slept with his housemate, begged for me back, then broke up with me. Now here's how it all goes

My ex hasn't ever been married. He was with a long term partner to which he had a child with, due to her infidelity they are not together.

Which leads me to why I am so confused, if he got hurt. Why would he do this.

I didn't trust the housemate because she was so unreasonable. When I would be there, she would stomp, slam doors, and send abusing texts whilst I was there so I could see them. So I think it was her who got her nose out of joint with the whole situation. After they had slept together he got a message from her. We were on the couch and it said I feel really bad because you have a girlfriend. He didn't relise I had seen it (and I get what he did was wrong, but we weren't official. And if he never wanted to tell me that was his business I thought) I thought she was just being malicious, because we both knew from the moment we started seeing each other she liked him, but he didn't like her. He told me he told her that it could never happen again, and that I wasn't going anywhere. She then skipped state for a few weeks.
I then only stayed with him because he begged for another chance, and when we talked about it he said well lets make things official, that way neither of us can hurt each other. Now he has nothing. We have both moved on (well I haven't, she moved 2 states away)

I know it sounds like I am defending him. But it wasn't just him. After everything happened I felt I had gotten myself stuck in a rut. It wasn't that I didn't trust him, I didn't trust her. He put up with me complaining, I kept bringing it all up. I made myself untrustworthy I think. He did all the right things, well tried to make me feel better about everything.

I tried so many times to end it, I couldn't deal with it. And he would just keep crawling back into my life. I guess this is why I am so angry and upset, all this time I have been trying to end it, and he got the last say. Now he ends it and I have no say.

I had to message him the other day, because he has some things he needs to give back of mine. And he wrote back (where as before he would avoid this whole situation together) during this process I told him I was going away, and he said oh well you have fun then, try not to get sunburnt. I wrote back are you kidding its me your talking about. Then I had to open my mouth and ask if he still had feelings for me. He said I have some feelings yes!!
But don't push the matter.

I see what he wrote to me was really rude. But after all my jerking round (and the occasional message asking why this all happened to begin with), I think now he thinks he has the right to do it. I just take it at least he still has feelings for me, which should count right?

It was so fast paced, I never intended it to go this fast. I never said anything to scare him away, he was the one who said it all. I never wanted to say anything to get anything complicated. Now apparently when I get back he said we would talk.

I know actions speak louder than words, and if he wanted me he would be chasing me. But he did ask for space. And told me that he thought we would have worked.

I know I shouldn't be blaming myself.

How can I get my point across to him, that things can be different. Without chasing him, without giving him the benefit of the doubt

All right, first of all, the only person you do have to blame is yourself. I don't mean to say this in a bad way, but you put yourself in this situation.

Do NOT blame the other girl. Your ex had just as much to do with this as she did. Girls tend to blame the other girl, and not look at the whole picture! Do you REALLY think this was one sided? Do you think she forced him?

Sure he has feelings for you! They aren't the type of feelings that you are thinking of though.

NOBODY can come "crawling" back into your life unless you let them, and it's obvious you want him too. Mark my words, he is not going to be there when you need him either. Is yourself respect so low that you are willing to let him send you rude messages, and then you say that because his words of having "feelings" for you erase that?. and that is suppose to count for what?

If you want to be walked all over on, well then keep on doing what you're doing, and you will keep on getting hurt.

This isn't my first time around the block hon, so trust me, find someone that is not attached, or you are headed for heartbreak!

I wish you well.