This is one of the biggest reasons straight men should not be friends with attractive females. An excerpt:

I really like you. I do. You’re so nice, and sweet, and you listen to all my problems and respond with the appropriate compliments. But, well, I don’t really see a relationship in our future. It would be terrible if we let sex destroy this great friendship we have where I get everything I want and you get nothing you want. Don’t you think?

The inevitability of this type of one-way friendship is exactly why I stopped being friends with unmarried women.