My boyfriend hides his phone...what do I do?

So my boyfriend hides his phone from me and I really don’t know what to do. I’ve talked to him about it but he doesn’t really seem to care. He just gets mad. I’m really concerned. I got onto his Instagram today and I didn’t find anything. I know all of his passwords. He keeps messaging someone on Facebook and he NEVER uses Facebook. What do I do? I don’t believe he’s cheating on me...but I just really don’t know how to handle this. He also just ordered my Christmas gift so I get he may be hiding his emails from me to see what he got me. Help a girl out!