My crush acted like a jerk but now suddenly he smiled at me?

So there’s this guy I have a crush on. I switched maths class in September so I was like the new girl, I wasn’t introduced or anything I just sat down and no one cared. In the second week, this boy turns around and looks at me and then at the end of lesson turns around and looks at me again. I was confused because no one turned around and looked at me as to who I was, but I was like maybe it’s because he didn’t come in the first week so he probably just realised now that there’s a new girl.

Then whenever the guy next to me would ask the teacher for doubt my crush would use it as an excuse to turn around and look at me.

Sometimes he turns around and looks at me at random times but that’s only a few times most of the time he does it because the guy next to me asks teacher to come help him so uses that as an excuse to look at me. He only started doing this after I walked past him and gave him a death stare this one time,( which was like a few days after he tried talking to me twice) after this one time he started doing this btw. One time it was home time and he didn’t really do anything. But before he was about to go to his usual way home he stopped walking and turned around and started looking for me. Once he saw me he turned around and continued walking

Now for 1-2 months he ignored me he never looks at me never really paid attention to me. He would turn around and look at me he would just go about his own business but this also could be because the seating plan changed and I sit right at the front so he can’t turn around and look at me even if he wanted to. In general he does nothing now when I look at him across the room and stuff. I turned around and looked at him and he avoided eye contact and when I walked past him he avoided again. Then he stopped walking and started looking for me again. But I don’t understand why. After that I stopped liking him because he clearly isn’t showing interest like he used to

So I stopped liking him and now today we had a maths exam in a huge hall and I walk out from where I put my stuff and he comes from the other side with a smile on his face looking at me, like it was literally directly at me I saw his face with a proper smile to himself but looked at me I was so confused smh

I don’t understand why because he ignored me for like 2 whole months.

Now you might think he’s shy but he clearly isn’t shy if he turned around and looked at me 5-6 times in the first week I tried to make it obvious I liked him. He clearly isn’t shy to turn around and but into a conversation me and a guy we’re having asking what I said when he didn’t even know me.

So I don’t know. Does he like me or is he just idk