Well, it's not surprising that you would have close feelings for a really good guy friend. Your emotions are what they are, so don't worry that you shouldn't be feeling the way you do.

However, if your friend really is gay and is not open to dating girls, it could be very frustrating to like someone who has declared that he is only interested in boys. Maybe take a look at what you like most about your friend and see if you can find those similar qualities in someone else who is open to dating girls.

It's up to you to decide if you want to tell your friend about how you are feeling, not tell him, or do something else. Keep in mind that if you do tell him, the way he reacts could affect your relationship. But things may change between the two of you if you keep your feelings to yourself.