I like a guy who's one of my closest friends?

If your feelings towards him increase, then you've got the biggest question to ask yourself coming up. He loves you as a friend and feels that he can confide in you with any subject. You have his utmost respect and confidence. If you express your feelings towards him and they aren't returned then you are back to square one and may lose him as a friend. But in the same token, you need to look after your own feelings. Ask yourself this.. If he started dating another girl now, how would that make you feel? if shattered, then you have to talk to him about your feelings. Maybe you need to make some distance at present and see how he reacts to not having you there anymore. This really is a tough situation and it is very similar to relationship break ups when one person wants to remain friends, while the other still harbours feelings. Those friendships never work and that's why I suggest you take a break. Good luck