Confused

So this guy I know is just like my best friend but he is also my boyfriends best friend he is a couple grade prove us but my boyfriend and him are very close because of being in band. And therefore we have become very close. But lately we will just be talking and he will say something about me Being cute or i bite my lip a lot just out of habit, during pictures and when I'm thinking and he told me it was very attractive and it doesn't really phase me. it never has. But the more frequent it happens the more I am maybe thinking it something I should be worried about. Should I be worried about this? Or talk to him or my boyfriend about it?