Should I ask him or wait for him to ask me?

Okay. So I like this guy and everybody says he likes me. let's call this guy Bob. So there is a dance coming up at our school and I really want to go with him but people say that Bob is too shy to ask me out. He is afraid of getting rejected. Normally I would just ask him to the dance but so far, every girl in my homeroom that has asked a guy out has been rejected because other guys heard and made fun of him. Even the REALLY popular girls got rejected! What should I do? I mean I know he likes me, but I'm just so scared I'll be made fun of. P.S. His name is not really Bob.