Why a guy would pick on a girl?

Yea, I'd definitely say he's flirting with you as long as he isn't doing it in a mean way or anything and saying that he loves fighting with you practically screams that he likes you, at least that's what it seems like to me.

He likes you. That's just his way of flirting with you.

Yeah I'd say he likes you too, that's their way of flirting. Do you like him? If so you should go for it!
Good luck

he probably likes you. that's one way of guys to get your attention. he probably has a crush on you but doesn't have the courage to say it. there were two guys in my class who kept doing that, found out later that they both had a crush on me, that's why.