Is he interested in me as more than a friend?

I have a massive crush on this guy I do martial arts training with. We see each other at least 2 or 3 times a week, and really get on. The other day I texted him to see if he was ok, as he'd missed training. He'd been ill, and the first line of his reply was ':-) how sweet' Does that mean sweet like a girl he might wanna go out with, or sweet like a puppy dog or a baby sister? Then yesterday, he came and talked to me on the the pretext of opening the window. After he's opened the window, he walked away from me as far as possible. Is he shy/avoiding me or what? I'm so confused!