How do I know if my crush likes me back?

Ok so i like thi sguy but i have a boyfriend. My crush is compeating against my bf but is also being a real jerk. He said he liked me, but now says he doesn't. He'll txt me every day just to say hi. When I asks hows he's been he asks why do you care. When i say i care about all of my friends he says who ever said i was your friend? Finally if something ever happens and he asks me whats wrong i say nothing and he instist that i tell him. then when i ask why do you care he says he doesn't. Everything is so confusing. How do Fix this and how do i know he really cares for me?