Why is he being so mean?

So I fell in love with this 23 yr old, I am 18, he told me he liked me, and I told him I liked him too, but it was bad timing, since his ex was still in his life, and he wasn't sure if he still had the same feelings for her as he use to. But anyways.. down the road, he keeps flirting with me, he is not with her anymore, but I let him know that I still liked him. I told him I was going to give it another chance in some time, to get with him, he agreed and simply said "Okay I will be waiting..." BUT. Now he is mean, I mean I know guys tease, and it's natural when they like a girl, but it seems like he teases too much like he is mad at me. He tried snatching things off my hands, tries to take my ID away, maybe I am taking it wrong. He is a usual teaser. But how can I tell why he is doing it worse now? I mean he still flirts, and tells me I am cute. but just the teasing is mean. What should I do? Is he trying to just push me away?