How does it make you feel when a guy tells you how he feels about you?

How does it make you feel when a guy that you've been friends with tells you how he feels about you when he knows that you currently are dating someone? Do you feel like he's put the "friendship" in danger by telling you when he knows you are seeing someone? Do you feel a little betrayed and feel that he's never really been your "friend" and was only using the friendship to hopefully make it lead into dating you? Do you feel a little weird about it, but ultimately you respect him for having the nerve to tell you? Thoughts please.