Fear of commitment or ego issue?

I had a crush (or so I thought) on a friend. He kept saying he didn't want a relationship and was enjoying being single, so I was really sad for a few weeks because I thought he knew and just didn't want me. I did everything to please him.

Now he's realized I want something, talked openly with me, and said he likes me too. We've been out a few times since then, both alone and with friends. He's actually been pretty open about the fact that we "have" something (holding me in his arms, hand on my leg, etc.).

Somehow, now that he wants me too, I don't find him so attractive anymore. Especially his looks. He's very handsome, which isn't the problem, but he's shorter than me. He also doesn't behave very "masculine," or rather, not the way I imagine my partner to behave.

Now I'm wondering if it's just my fear of commitment, as I think, or if it was just an ego thing, to make him like me back. I've had situations like this before, and since we haven't even kissed yet, it probably wouldn't be so detrimental to our friendship.