tell your parents you are going to bible study, then sneak off to the hodown!!
hire a hypnotist, get him to hypnotise your parents into thinking that bboy hodowns are pretty much chess tournaments then theyre sure to let you go!! also get him to hypnotise them so that anytime someone says hello to them they bark like a dog, just for funzies
get one of your friends with a car to wait outside of their work, then as they are crossing the road he will race towards them. now you run up to them and push them out of the way in just the nick of time, thus saving their lives!! after that theyre sure to let you do anything up damn well please, (and probably get a raise in your allowance while youre at it). this one does have some issues tho, like if the timing is off by even the slightest it could spell disaster... but then I guess you would still get to go to the hodown, providing the funeral isnt the same day...
oh jokes, ok I'll stop. Maybe you should just ask them. dancing is obviously one of your fav hobbies and it is great exercise, its more fun to do it with other ppl, its a great learning opportunity... I dunno list all the positive things about it, formulate it like a debate, compromise with them if need be...
hope that kinda helps, best of luck!