My best friend in love with me?

Yesterday i asked if my best friend was in love with me, he always flirts and when we hug he lingers, but he's just joking right? Anyways, I dont undertand why that whenever i talk about me and other guys he gets really quiet, and really angry, and then i tell him that i might be intrested in a relationship w/ a guy who lives two hours away, and he just gets snappy and says that its a waste of time...but why should he act like this when he has had previous relationships and is currently in one? Please help me!!