My ex boyfriend is being a little confusing (with teasing me playfully) can someone decipher whats going on?

My ex boyfriend I dated for 2.5 months broke up with me 2 months ago, but claimed he still wanted to be friends. We are both in high school, and we share the same extra-curricular activities, therefore I see him very often. he calls me “midget” ( some other friends do too, I am 5’0) and teases me a whole lot. We are in trivia together, and I answered a pop culture question. He said “because that’s all she’s good for” with a smile on his face. We say the same thing at the same time a whole lot (its so often its disturbing) or I say something and he’s says the same thing after I do. He also pretends like he’s going to hit me with things,(chairs, books, etc.) but when I said “I know where you’re ticklish” he stopped for the day. He also play fights. He doesn’t tease his other friends like he teases me (we have MANY mutual friends). I asked him to pass me chips and he ignored me, but then our mutual friend asked (who was sitting to my right so my ex passed the chips to him.And other times, he seems so distant when I am in the room. Any idea what could be going on? Possibly inner conflict?

We broke up because I claimed I loved him. He’s never had a girlfriend before me; he’s also a bit anti social; (some believe he has a bit of aspergers, he tries to avoid anything public, he tilts his head while talking and can only make eye contant with certain people) he’s also going to college & has never really gotten close to anyone like me. We were also each others first kiss, and we cuddled A LOT.
I wrote him a letter confessing my feelings for him; he also behaved a little more distant after our first kiss. He told me he had a great time being with me at my house, but he suddenly just slowly seemed to back away a little I guess. I told him this in the letter, with all my confusion. two days later without any text or call, he broke up with me at robotics saying “You are taking this to a level of intimacy I never intended to get to…I’m sorry Rachel..You’re a good person.. we can still be friends.” and he hugged me. I told him “You know we don’t have to be that serious at all..” and he just shook his head kind of