Do I really love my best guy friend without knowing it?

If you date him there's a good chance you could screw up a great friendship. Accept what you already have, friends who become lovers tend to lose a level of intimacy rather than gain one. Be his friend and you'll have each other for life with no complications. Would you have considered being more than friends if everybody hadn't kept mentioning it to you? You risk losing something special that you already have. Is it worth it? Only you can decide.