I just dated my best friend, for the longest time I had the same fear, telling him how i felt bc I was scared to lose him as a friend. Then one day he told me that he liked me & had for a while. He was scared to say something, bc he didnt want to lose me as a friend. Sometimes you just have to take the risk. Who knows, the person may feel the same way you do.

why not just flirt first and see what kind of reaction you get?

depends how good of a friendship you got