The Big Bang Theory cast surprises showrunners and audience with "Call Me Maybe" flash mob

The cast of CBS' The Big Bang Theory sure knows how put on a show.

Led by co-star Kaley Cuoco, the Thursday night ratings juggernaut surprised showrunners Chuck Lorre, Bill Prady and Steve Molaro during the Oct. 23 live taping with a coordinated flash mob set to Carly Rae Jepsen's summer hit "Call Me Maybe."

During the bit, the seven cast members -- Kunal Nayyar (Raj), Simon Helberg (Howard), Johnny Galecki (Leonard), Mayim Bialik (Amy), Melissa Rauch (Bernadette), Jim Parsons (Sheldon) and Cuoco (Penny) -- feign surprise when they see the crew break out into dance as they prepare for a take with the trio of showrunners looking on.

Ultimately, five of the seven -- save for Galecki and Parsons' notoriously antisocial/neurotic Sheldon -- join the group performing a routine choreographed by Cuoco's sister Bri Cuoco -- to Jepsen's song, much to the showrunners' and live studio audience's pleasure.

Check out the video, which was filmed during the episode that airs Thursday night and intended as a surprise for the audience and exec producers, below.

Source 1
Source 2