<human>: Can you condense the text into a few key points?

We were friends before, but ended up hooking up a couple of times over the past couple of months. There was a period of time where we sincerely thought that we both really liked each other and there was something there (things have always remained casual and not serious). The main reasons it ended were that his feelings were not strong enough, and that my feelings were stronger which created pressure. For me, obviously it was unpleasant, but it turned out that my feelings were not that strong and I was actually completely fine with it (I didn't feel the usual anxiety, sadness, or particular urge to contact him).

The problem is that I would actually like to remain friends with him, but after it ended I felt like his behaviors were a bit hostile towards me and I'm not sure whether and how to proceed. All the incidents are very mild but they do add up. For example, he would talk in a mildly unfriendly manner towards me, but to the point that even our mutual friends pointed out that he's being weird, or that he would be relatively cold towards me, or that he would make meaner than usual remarks about me. I'm not sure what could have prompted this change in attitude. 

It's been a while since things ended, during which I haven't contacted him (a mixture of me not feeling like it, and given his reasons for ending things I think we needed the space anyways) and he hasn't contacted me, but I'm hoping to start hanging out as friends again (coffee, dinner, movies, etc). But now I felt really uncomfortable asking him to do that given his mild hostility. If I confront him about it he would probably say that I'm mistaken (I may well be, but I don't think so). So I'm curious what prompted this attitude... A male friend of mine suggested that these behaviors might be a reflection of his own insecurities and jealousy. I have considered that idea but havedecided that even if it's part of the reason it can't be the whole reason.
<bot>: friend and I ended a short non serious relationship, now said friend is being mildly hostile towards me, and I'm not sure if I should try to keep the friendship. (If yes, how?)