Why is my crush acting so weird?

k so i'm 13 i like a guy in 8th grade. but he's been acting a little weird for a few days... when i'm at recess i'll probably take a glance or stare at him for a few seconds then he'll look right at me for a few seconds to and walk over to me a my group of friends. also yesterday at lunch he sat at one table that was a little far away and i sat a another table. then i saw him staring like straight at me for a few minutes. we always talk everyday with my friends to but i never actually caught him staring at me! he would also ask these weird funny crazy questions about my brother lol... but i think he just did that to make my brother embarrased about his girlfriend. yesterday he also said something else but i didn't quite hear him lol then after he said it he patted my back and he smiled at me (we were talking alone when he did that. i think he's acting a little strange.... why do think he might be acting this way?