The two will be seen grooving to wedding number, "Lut Gaye" in the film, which they reportedly wrapped up in just a day.
"Director Abhinav Kashyap had kept three days aside for the shoot of the song, but to his and entire unit's surprise, Ranbir and Pallavi finished the song in just one day. When they started shooting for the song, the two got in to the groove and decided to finish the song the same day," said a source from the film.
A peppy wedding number, "Lut Gaye" is sung by Mamta Sharma and Aishwarya Nigam. Its music is composed by Lalit Pandit, while the lyrics are penned by Nikhat Khan.
Actress Pallavi Sharda, who was last seen in "Love Breakups Zindagi" is said to be a trained classical dancer, and that made it easier for her to match her steps with Ranbir.
"Besharam" is a comedy film, which also stars Ranbir's parents Rishi and Neetu Kapoor. The film will release Oct 2.