Crushing on a boy who's difficult to read...what do I do?

I’ve liked this guy for about a year now. (Let’s call him Mark.) We’re both very shy, and I don’t know if Mark likes me too. I’ve invited him places, but he always had something going on. In return, Mark’s invited me to a few of his band’s concerts, and I’ve gone each time. The first time he invited me to one of his concerts, he didn’t pay that much attention to me, but I didn’t take it personally because, hey, we’re at a concert, he’s with his friends, I’m with my friends, and it’s very loud in here. The second time, however, he REALLY wanted me to go. Saying, “I didn’t want to bombard you earlier, but now I realized I wouldn’t want to NOT ask you to be there,” “it’d be really awesome if you came,” and, when I said I could go, “THAT’S VERY FANTASTIC.” And, at the concert, I noticed that Mark made sure to say hi to me, dance near me, ask how my trip to the concert was, and to say bye when I was leaving. The few times we were alone, he acted differently from if we were in front of more people. Not in a bad way - it was good because he was more open about himself, towards me, and towards anything we talked about. He’s teased me a few times, we’ve bonded over art, literature, YouTube videos, and more, sharing many laughs. (I’m sorry for the cheesiness of that paragraph, I couldn’t find a better way to word it.) In public, Mark tends to be more shy towards pretty much everyone. However, he gave me a high-five for celebrating a job well-done on a project we had to put together/present not too long ago for this club we’re both in. I think he’s getting more comfortable around me/the people in that club, but I really don’t know. We really only talk about the club and the invitations we send to each other when we talk via text message/Facebook, which is the only time we talk to each other outside the club. I’ve also noticed some of his friends being nicer to me, but I also got to know them better before I really got to know Mark. But his friends and I lost touch towards the beginning of the school-year, and now I’ve noticed them saying ‘hey’ to me more or starting small conversations with me. I really don’t know if I’m reading too much into this, to be honest with you all.

I really hope this post makes sense. What I’m trying to say is that I really, really like this guy, and I don’t know if he likes me back at all. If anyone understood this post, please help me!