What do I do when I want my ex back and I feel I have ruined everything?? HELP!!!?

I am freinds with my ex. He broke up with me at the start of the year from about a 3 year relationship were we were each others first everything. I took some time out, re gathered myself etc & then we became friends again. He has asked inappropriate questions before like, have I slept with anyone else? Do I have a boyfriend? If i get a text message, who is it from? If I even text in front of him he asks if he is not interesting enough? He still finds me attractive and when we met for the first time after the break up he cried in front of me because it was sad? I have never asked him any of those questions bak. We were friends for years before we started dating & I guess I didn't want to loose that - even now I don't. We have alot of mutual friends & my best friend is his house mate. I think I have sort of supressed my feelings rather than dealt with them & I'm not going to lie as I guess on some level I really do want to him back. Last night we went out for dinner & to see a movie - we do this regularly & it has never been a problem before. Last night was not the same - I felt recently that maybe he was ashamed to be seen with me or something. I invite him to things all the time & he doesn't do the same. We discussed that & then he said something which triggered a nerve & I got a little teary and defensive. Then I let my guard down & told him that I didn't want anyone else atm, I wanted him & I will never understand why he broke up with me as his story always changes. He asked what could he do? He just wants to be single & friends with me. I'm not sure if maybe he likes me being around so he can have his cake & eat it too. I said well if friendship is all your offering then ok that will have to do. I apologised & he accepted. He's going away tomorrow on a holiday which will be good for him & me. He is having a breaky thing tomorrow before he leaves...do I ask if i can go? And how do I fix what happened last nite?