Shayk, 27, and Ambrosio, 31, joke with the busty brunette before pulling the move.
In another sequence, Shayk - currently dating footie ace Cristiano Ronaldo - frolics in the sand with another male model.
She then belly dances in a sexy black crop top as a man plays along on a guitar.
The promo video - for the dance-themed CR Fashion Book - also sees the pair shake maracas and sexily wiggling their hips.
The film also features dancer Lil Buck who has just returned from touring with Madonna.