Search Results: he has a lot of girls chasing him

So generally, I'm not sure if I'm that good at knowing if guys like me or not, so I was just curious about how my thoughts compare to those of others. Anyways, so I'm a competitive swimmer and recently there was a training camp for a big meet. So there was this guy that joined this year but I haven't spoken much to because he is in a lower class. However, camp is less segregated so we saw each other a lot more. I wasn't that friendly with him before, but during the camp, he starting talking with me a lot more and making jokes and all. He starting following me on instagram. And then one time during the lunch break, one of my friends stole my phone and he got up and helped me chase her down to get it back (I didn't ask him to help, he just did). I feel like that is sort of a kind of protective, show off, hero type thing guys try to do when they like a girl. Over camp, I just started getting the feeling that he liked me. But then at the end of camp I learned that A. he has a girlfriend (of a month at that time), and B. he actually a few years younger than me (he's 13 and I'm 16 (also I know my profile says I'm 18, but I lied there)). I mean he's still in middle school and I'm in high school so that's a big gap at our age and he seems to really like his girlfriend. But then again, middle school relationships aren't really that serious. I don't know. So, does it sound like he liked me or was I way off?

Just to keep the story shortm, im going to bullet point everything.

Met online, talked for nearly a year
We liked each other, but i wanted commitment and he "didnt know what he wanted"
Stopped talking, no contact at all for like 6-months or so
He breaks ice by messaging me on my birthday
And then subsequently slowly starting to message me abit more (I was a little cold at first)
Then i started responding a bit more, thought if nothing else we can be friends i guess (Cause we got on so well)
Been talking again for about 2-months now, and were back to our usual selves (Flirting like crazy, we both definitely have the hots for eachother)

I still have feelings for him, and it seems like he does for me too, but im too afraid to ask him why he's back and what he actually wants. (Dont want to get hurt again, but equally still like him lots)
Best thing this time is that he started talking to me, and he is initiating mojority of the conversations, and seems to be doing the chasing this time
He compliments me a lot, he does bug me a lot too as in a lot of banter, but i give as good as i get, thats why we get on so well

My theory: Why would he come back to the same girl who he knows has feelings for him if he didn't want anything more. Do you think the 6-months or so have made him think about us and made him miss me?

So a question to all the lads out there, if a girl told you she had feelings for you and you freaked out and dissappeared, why would you be back?