How do i know if he is Bi or Gay?

Well i am bisexual and i like this boy and i dont know if he is gay or bi or straight. he always gives othere guys hugs and he keeps trying to hug me but i dont want to hug him because i might slip and say somethig like i like you or whatever and when he does try to hug my i say something like boy move or something playfull or whatever. Then he saids ok what ever and walks away with a pissed look. In class the guys play to much and touch each others asses and all that stuff i dont do it because i do nt like being touched much because i like when my skin stays fresh and clean from my shower. So when a boy trys to touch me on the *** or hugs me i push them off me.Because i dont usually like boys mostly girls. but the boy i like i love when he trys to touch me i let him sometimes. So i would like if someone would tell me the signs if someone is gay or bi