Ranbir Kapoor has done his first item number in a promotional video for a children's flick, Vikas Bahl and Nitesh Tiwari's Chillar Party.

The actor was "super excited" when approached, says our source. He "loved the idea (of the film)" and "readily agreed" says director Bahl.

Ranbir plays himself in the video. It was shot in one day.

A source present at the shoot reveals, "RK had a great time during the shoot. He was seen bonding with the kids.

In fact, he picked up lot of steps from the boys in the movie. It was a very impromptu move on his part. He connnected with the kids instantly and they had a ball on the sets."

Mix track

While Amit Trivedi has scored the music, Bosco-Ceasar choreographed the song. The source adds the song is a mix of street instruments and local voices. Amit and his mother will croon for the track.