Hmm, well my first advice would be to look him in the eyes when you ask him to the dance 0.o yeah I know that's really hard sometimes, but it will probably make him see that your serious. And if he says no, first you could tell him how you feel- not just that you like him, but that you were nervous about asking him to the dance and that you know he hates you. He might see things a little differently once you explain yourself

and if he still says no, hey, life goes on! You could find someone else to go with, a guy who doesn't hate ya! You never know...

I really hope this helps you! Good luck ^^