My clmate playfully bit my arm, is he flirting for real, or is it for his gain?

Okay, I'm gonna break down the entire thing. My friend/clmate sits next to me in history cl and we usually talk to each other when cl is boring or just cause we don't wanna pay attention. Sometimes it's pretty smooth and he makes me laugh and smile pretty easy, to the point were my cheeks hurt like hell, though keep in mind, P.E. practically makes me high enough to laugh at clouds, plus my own jokes usually crack me up, only its slightly different when he makes me laugh. He only really talks to me in history cl, sometimes in science, and if sometimes he comes over to talk with my friend Amari with his two other hot-and-skinny, short guy friends. He's friends with ALL the guys I think are hot, but he has a girlfriend, well I think so anyway...He hangs out with this group of "ding-dong-dang! their stupid blondes!" and he holds hands with and hugs them a lot, one a lot more than the others. Keep in mind I'm like five sizes bigger than them in three ways, only one being good. Though they are really REALLY short and skinny, but they're exactly the same height and waist size as him, so I'm not that bad off because I'm one of the tallest girls of my age so people often mistake me for four years older than I am. I have really bad acne and my legs and *** are probably the worst part of me, my waist, my eyes, and overall face look are the good, so I don't feel self-confident very much, and I only act myself around my closest friends and if they strongly disagree with something I say as if it's completely wrong even if it's an oppinion, I often feel hurt and recoil quickly, keeping my mouth shut. When we're not actually talking though I am extremely cut-loose crazy fun when we are talking about normal things like games, clwork, and hobbies, and we often 'modify' the games we're supposed to play in P.E. and-I'm getting off topic. Anyways, we were in history class taking notes and finding information on an informational read-out sheet and I commented to him that in kind of looked like a Chili's Mexican Menu and he agreed. He started going on about chimichangas, burritos, and tamales, so I just continued my work. After about 3 minutes, he scooted his desk hecka close to mine and leaned in towards me. I kinda threw him a "Uhm, okaaay" look and tried to write more, with the added difficulty of his face being close to mine. All the sudden he says "Psst. Hey, what'd you get for number three?" I reminded him that it was a note-taking sheet and it wasn't numbered. He said oh yeah and studied my paper so I just figured he wanted to cheat and let it slide, only he wasn't copying my work and we weren't actually working together as partner, just to clear up why my teacher didn't smack him with a ruler for doing that, but no one else move their desk close to their partner. I continued working and all the sudden my leg hurts and I go, "Ow, something just bit me!" cause a bug actually bit me. Then he goes, "It wasn't me I sware!" I look at him weird and he just smirks. Then his friend Eddy (who sits on my other side) starts harassing him. "Suuurrrre we totally believe you. But why are you getting so close to her, huh dude?" Okay because I don't wanna use his given name, I'm using the name Genie as his alias because that's actually my nickname for him, that way you don't get confuse him with Eddy. 'Genie' got up to walk around to Eddy and I returned working by myself, much easier without my face turning red. After he talked to Eddy for a while I felt a slight but not uncomfortable pain in my arm. I turned and saw 'Genie's' face right next to my arm and he smiled cheekily. "It wasn't me I sware." I thought he pinched me but his face's position, the slight teeth marks, and wetness on my shirt's arm would prove otherwise. Is he flirting? Is he just acting like that because I'm the only girl who sits near him? Does he actually like me? Or is it just his way of insuring I let him cheat off me later? Please help! Remember I'm not sure if he has a girlfriend or not. Also I wear glasses and most of the girls at my school don't, so could it just be a stupid glasses fettish? Am I completely over reacting and should I ignore it? Should I go for a different guy? Help me, I'm desperate!!! -Not in that way pervs-