I'm so confused with this guy.

So I got to know this guy through a society in school. He's a really nice guy. And I kind of have a crush on him now. We used to say hi when we bump into each other. I requested to follow him on Instagram but he did not accept. He is active on Instagram and frequently posts new photos and accept follow requests. Nowadays , when I say hi to him in school. He sometimes ignore it intentionally or unintentionally. But when my another guy friend and I talk in the society meeting. He'll come over and talk to me as if we're beat friends. I'm really confused . Advice and opinions pls.