Why do you think he's acting this way to me if we are friends?

There’s this guy in freshmen year(hs) I’m in 8th grade. When he was in 8th and I was in 7th we didnt get along very well Due that our friends made sh!t up about us… We used to fight everyday Over stupid reasons! I pretty hated his guts lol, but for some reason I started Liking him…I really didnt tell anyone since we were talking sh!t about one another. Well I would notice he always had his eyes on me! He was always staring and when I caught him, he would look away or to the floor. His mates would tease him about me when I was there, but he would ignore me. Everytime I talked to other guys he would get soo jealous! Lol finally we became ‘friends’ though we really dont talk. When I try to talk to him he gets all shy and nervous! And I’m like wtf? We have hugged more than we have talked. Lol he says yes to everything I ask him to do! Lol its pretty funny actually, becus I ask him later and hes like completly forgets about everything! Recently, this wednesday I told him I had a boyfriend. He looked weird. He was in a big hurry to his bus and he stopped and said what??!!! And looked me in the eyes like he had never had before! I told him..you didnt know I had a boyfriend? He was like noo. He said send me a picture. I said a picture of what?? But he left running up the bus! He put on his social website ‘dont wait till its too late-not of this world’ is that a song? Lol I thought. I really dont know whats going on! Yesterday(friday) he was mad at me! I told him’hey remember I told you I had a boyfriend?’ and hes like ‘ohh yeaa… Boyfriend yeaa’ but I couldnt even tell him anything because I kept on screaming his name and he ignored me!! What do you think is going on? I want to make it clear I dont have feelings for him anymore. I’m just confused with his attitude towards me? I dont understand him and im guessing someone can help me figure out this puzzle? He still stares me at me. But now not as usual since were in different grade levels. Any help? I dont understand why hes like this if we are friends!!!