The best thing about the Vanity Fair party? The A-list pairings unique to the most exclusive WHCD parties. What exactly was Attorney General Eric Holder talking about with Questlove?

“Afros,” said the musician. Holder had an Afro 30 years ago and used to wear a pick not unlike the one sported by his new BFF. Apparently it’s never too late to grow out your hair, even if you’re a cabinet member. “I told him he should,” Questlove said.

And so, the party for grown ups: champagne, lobster, Peking duck, and A-listers everywhere making VIP small talk.

The annual after-party moved to the Italian ambassador’s residence, Villa Firenze, a gorgeous Tudor mansion overlooking even more impressive grounds. But it was too chilly to linger outside, so all the action was jammed inside, vibrating from the center hall.

Yes, that was IMF head Christine Lagarde, tall and tan in a pink lace gown, chatting up a rumpled Robert DeNiro. The topic? “Raging Bull,” the first movie she saw him in. “I asked him if it was true he gained all that weight for the role, and how long it took to lose it.” (Six months.) World economic leaders — fans just like us!

So many boldface names. A smiling Chris Christie didn’t seem a bit bothered by all those fat jokes. Besides, sexpot Sofia Vergara almost knocked him over when she jumped into a picture with him. A fan? “I’m a fan of anyone who means well for the country,” she cooed.

Nancy Pelosi. Julia Louis-Dreyfus, wearing wonky black glasses. Valerie Jarrett. Susan Rice. The “Scandal” crew, who seemed to win this weekend’s popularity contest, not that anyone was voting. Actors who play politicians. Media stars. A few people who looked famous, but weren’t.

The most unexpected guest was Darrell Issa, who rarely surfaces at any D.C. party. The Republican congressman flew in from California just for the day, and walked into the crowd like a man who had real power. As chair of the House oversight committee, Issa said, “I have an interest in all things about D.C. — and that includes Washington’s social life.” Then he just smiled.