Ranbir Kapoor & Deepika Padukone 'NAGIN' Dance for "TAMASHA"

Here is a treat for all you 'Tamasha' fans. A video leaked from the sets of the movie is making the rounds. It has Ranbir Kapoor and Deepika Padukone performing for a sort of a funny 'nagin' dance. Can you tell what is going on here?
Ranbir and Deepika are shooting for Imtiaz Ali's 'Tamasha' in a beautiful island Corsica, which is to the South of France. On this particular day, the ex-love birds were seen practicing for a song sequence.
Produced by Sajid Nadiadwala, Tamasha's music is by none other than music maestro A R Rahman.