How can you tell if an older guy likes you?

Ok so I have had an insanely huge crush on this guy ever since elementary school, but the problem is that he is almost 20 and I'm 16. Once I was old enough to see it was never going to happen, I began to think of him as an older brother when we were around each other, but that crush was still there. Well now I'm 16 and he has randomly started to text me non-stop all day. He's also asked me to come hang out with him and his friends, and we have a blast when we do this stuff and he has every quality I could ever want in a guy, but I'm not sure if he likes me or if I'm still just like the kid sister. When he texts me, he doesn't seem very interested and he seems oblivious to my obvious attempts at flirting through text and completely brushes them off, but when we are together in person he's smiling and he hugs me and we wrestle each other in the pool. And every now and then I will get a flirty text but it is always very short lived. He is unlike any other guy I have ever met and I would be ecstatic if we got together, but I can't tell if he really likes me or not. Please help!!!