Most Helpful Girl
One of two things could be going on.
Either he has an understanding and agreement with this girlfriend of his where he can date other girls. And in this case he's probably struggling with it, and wants to find someone else. He seems to like you, he bothers to talk to you every day and he did publicly kiss you in front of people in his own town of residency, so it didn't seem like something he was afraid of getting caught from. If this is the situation then you're probably going to lose him once he realizes how you feel, and then you might not like it, especially since you'll probably want him more when you can't have him, so you'll be left wondering what could have been.
Or he is an asshole that just wants a hook-up, and not just one hook-up, but a guaranteed one for every time he gets to see you. In this case, he's probably talking to you every day, because he has the time to, and so he might also be talking to other girls too. Especially since you're in a different state, he has the advantage of not getting too serious, not getting caught, and also he has the advantage of being able to do this with other girls in other states as well.
And a side note: he only sent you flowers, he didn't come out to see you, or do anything more personal like send over a bottle of your favourite drink or call you on the phone and talk for a while. So he most likely sent other girls flowers too.
Originally, I was thinking he was the guy described in the first case, but now... Other people might not agree with me here, but I'm leaning towards the second case. Although you shouldn't disregard the first scenario so soon.
You should talk to him, get the truth out, ask for complete honesty. Don't let him fool you twice by lying to you and you believing him. Be precise about what kind of answers you want, but at the same time, keep an open mind. You seem like a kind-hearted person, worrying about the woman and all that, but you should put on your selfish shoes for a while and think of what's best for you, even if it means hurting someone else, because from the way he described her, she doesn't seem so nice. Good luck to you, it seems like you're going to be dealing with some confusing feelings very soon. Sorry I rambled on, it's just that I found you're situation interesting.. Oh, and hope for the best, expect the worst, and prepare for everything!