It's a tough call.  I told a girl I'd had feelings for her for over 12 years, and she stopped taking my calls (even though I'd been her best friend the whole time.)  On the other hand, I resisted telling a girl about a crush only to find out years later that she'd had a crush on me at the same time and never did anything because she didnt think I was interested in her.  You have to go with your heart on this one.  If you absolutely adore this guy take a leap of faith and hope he catches you.  If he leaves you hanging it wasnt meant to be.