Ben doesn't know it either - dances change so much over the millenia, any dance experience he has is irrelevent. But he does finally down the rest of his glass and places it by a wall out of the way.

"Shall we learn it, then?" he asks, holding his hands out to her as he steps right into the dance. "It's easy, you just do what they do."

It's not even about not stepping on toes. If you hone your reflexes just right, he'll demonstrate, you can take the steps at the exact right time.