Oh! I thought it was a type of dance. I knew it was rhyming slang for laugh, but just didn't think that was what he meant.
Edit - lol! I've just looked up 'bubble dance' and I was right, it is a type of dance, but I don't think that's what he meant! I think I was thinking of the Bogle dance move, from the '90s. Who remembers that? Laugh is probably right then!