You should just tell him.
How do I tell my friend that I like this boy? I've liked him for about 2 years now and still haven't told anybody. I'm nervous that she will tell him. Do you think I should tell him or keep it to myself?
First see if your friend is capable of keeping secrets... Then tell her okay.... And if you're scared she'll tell the boy, why don't you let go and tell him? It's been TWO YEARS and you have told no one! Just go and tell him, tell him how much you like him and express your feelings so just tell that boy, why tell your friend?!