Rihanna's Night at the Museum: Perform and Party

The 21-year-old songstress performs with Kanye West, followed by some late-night club-hopping

You've all heard by now that Rihanna returned to the red carpet last night at the Costume Institute Gala in New York City.

Once inside the Metropolitan Museum of Art, she sat at  Marc Jacobs' table with Madonna, Victoria Beckham and Stella McCartney.

The 21-year-old Barbadian beauty was also the suprise performer of two songs with the night's entertainment headliner, Kanye West…

"Kanye asked her to do it," a source tells me. "It was his idea, but [Vogue editor-in-chief] Anna Wintour obviously had to approve it. Anna was at the run-through during the day and was so into it."

After things wrapped up at the museum, Rihanna was spotted at Jacobs' fete at the Monkey Bar, chatting with Gossip Girl star Blake Lively.

She also hit Bungalow 8, where Harvey Weinstein cohosted a party with the legendary hot spot's owner Amy Sacco. "I saw Rihanna with a couple of girlfriends," a fellow clubgoer reports. "She danced and was having fun."

Also packing it in elbow-to-elbow at Bungalow were Mary J. Blige, Liv Tyler, Kate Hudson, Kate Bosworth, Weinstein's Marchesa designer wife Georgina Chapman, Claire Danes, Ashley Olsen, Eva Mendes, Jessica Alba, Kate Perry, Kerry Washington, Anne Hathaway and Kate Beckinsale, among many others.

________

Follow Marc on Twitter @marcmalkin