Not sure what to make of hook up with ex?

A couple days ago I ran into my ex (of 2 months ago) at a bar and in the beginning of the night we pretty much just ignored each other, but by the end of the night he was texting me and we ended up at a table talking to each other for some time. Well then we came back to campus separate from each other, but he started texting me again (we hadn't talked for almost a month before this because i realized how i couldn't be just friends with him), so i ended up going over to his house and hung out and talked, which eventually lead to us hooking up even though we both knew it was probably a bad decision and that things aren't going to change, so i realized this and didn't text him or anything b/c i just saw it as a moment of weakness, but he just texted me last night just to talk about random stuff and it's not like i can go over or anything because i'm home now for the summer. He eventually brought up a couple nights ago and just said "so, what'd you think about the other night?" and i just said that i found it interesting and he said how he didn't expect it to happen and when i just responded with "yeah, nope" he never said anything back after that...i just don't know what's going on in his head, i mean i was under the assumption that it was just something that happened because we both were a little drunk and that to him that's all it was because it was convenient at the time