Oh No, I Think Cheated . . . And I Think They Both Like Me :s. Help?

i’ve been ‘seeing’ this guy for a little while now, around a month. we met at a party and he seemed cool, we danced, the next time we met, at another party, we made out. then i went away, got his number when i came back and he asked to meet up. we went on a few dates, didnt kiss untill the second one, and then he invited me to a theme park with his dad and stepsister – we acted like a couple the whole day. he always held my hand or had his arm around me and we kissed several times.
made plans to see him twice this week as he goes away for 2 weeks on saturday . . . made more complicated by the fact that i leave for uni in september, about 2 weeks after he comes back. so. we’re not official, hes not my boyfriend, but it seems to be getting that way. we haven’t spoken about what to do at uni, if we should try and make it work or just break it off cos the distance and me being away will be hard.
also, his ex comments on his fb with ♥’s and stuff, and he gives her loads of xxxxx’s, and shes just tagged him in an album of when they were together and made it her dp. so i thought that was a little weird.
then last night, im in town for a mates bday, one of my friends who im not as close with as some others but nearly had a little something with months ago asks me if i want to go outside after he bought me a drink. i say yeh sure, and we sat chatting for a while about this guy im seeing and how hes been hooking up with this girl he used to like – he said ‘we’re not going out, but if she asked me out i might say yes’ and theyre off to the same city for uni so she said they could wait till then – shes using him as a backup basically.
so then he asked me to walk around the block with him, we went down this quiet street and he stopped and said ‘so do you think this ____ guy would mind if i kissed you now?’ i was pretty shocked and just kinda said ‘yeh i think he would!’ so he said ‘what about you?’ and kissed me. and i kissed him back! i was really caught off guard and the thing is i’ve always had a soft spot for him and he reminded me of that!
i told him i dont know what to do, and we both said if we want to forget it then we’re cool with that, but neither of us really wants that, but we dont know what we actually do want. what with uni being like a month away.
the thing is, he said ‘i just think you can’t have been that into him if you kissed me back’ and i think he might be right. what if i wasnt as into the first guy as i thought i was? what if the second guy texts me now hes sober (as he said he would) and says he wants to forget it – do i keep seeing the first guy? i tihnk i like him, but then do i tell him about this? we’re not bf/gf but the thing is i dont know if we would be. especially with uni coming up!
and im seeing the first guy in a few hours! do i tell him but keep seeing him if he will, do i not say anything? do i break it off? ahhhhh
sorry this is an essay. any help??? can’t ask my friends as i dont want them to know in case he wants to forget it.