Do you think he fancies me?

There is this boy at my school called Aaron and I used sit next to him in English, we basically talked and laughed the whole lesson. Out of the lesson though he doesnt talk to me, but he smiles at me in the corridor. The teacher changed seating arrangements so now we dont talk at all. I fancy him, but I am too shy to ask him out - what if he doesnt like me (basically scared of rejection and him telling his mates an them laughing)