Why is my friend acting this way?

Alright, so hes being weird. I talk to him at my locker, in cl, etc. But lately, he likes to walk to cl together, he IMs me, and he says hi to me first thing in the morning. BtW-hes not a good friend, hes just someone I've known for a loonnggg time. So whats up? I need help ay-sap.