No Regrets: Katy Perry Comes With Extra Cheese

Like confetti shot out of a cannon, hundreds of brightly colored wisps fluttered around the city after the Met Gala on Monday night, landing at after-parties that went till morning.

The first stop was a party given by Gucci, a gala sponsor, in the Hunter College gymnasium (“Home of the Hawks!”) on the Upper East Side.

Dolled-up partygoers like Katy Perry, who had changed into an enormous cheeseburger costume, were escorted by attendants down the treacherously steep bleachers to the basketball court, where waiters served pizza bagels, mini corn dogs and sliders.

It was almost easier to spot who wasn’t a celebrity in the humid throng, which included Miley Cyrus and her husband Liam Hemsworth; Demi Moore; Jordan Roth; Chris Rock; Darren Criss; and Jared Leto, still carrying his severed-head prop.

“When you think about camp, you think about setting yourself from the beaten path,” said Dapper Dan, the Harlem designer and stylist who has lately been celebrated by Gucci. “All of the outfits, the themes — I had a great time.”

Elsewhere in the gym, Lauren Santo Domingo, the socialite, lit cigarettes for herself and Sienna Miller, the actress. They reclined on a sofa next to Emma Stone and Carey Mulligan, all of them in metallic or sequined dresses, like a row of beached mermaids.

Alessandro Michele, the creative director of Gucci, mingled with Wendi Deng, Harry Styles, Mary-Kate and Ashley Olsen, Bette Midler and Alexander Skarsgard.

Corey Johnson, the New York City Council speaker who has mayoral aspirations, said he had attended the gala at a table with other elected officials. “We were off in the corner like the island of misfits and lost toys,” he said.

The next stop for some (although not many) was the Moschino party at the newish Playboy Club on West 42nd Street.

The club, which radiates expensive, hormonal kitsch, is on-brand for the label. But the party never fully got its mojo, even with appearances by Jeremy Scott, the designer of Moschino; Gwen Stefani; and Katy Perry, still dressed as a cheeseburger.

Christian Combs, son of Sean Combs, the rap impresario, did not go through with a planned performance at 1 a.m. A Moschino spokeswoman blamed “unforeseen technical issues” for the cancellation, but the impression among those present was that he didn’t want to sing to an empty room.

Lack of attendance was not a problem, however, at the Top of the Standard. The party, now in its 10th year (remember when Solange Knowles and Jay-Z had that fight in the elevator?), was so heaving with celebrity names that it could have been a parents’ orientation at the University of Southern California.

After Lizzo performed her hit “Juice,” Idris Elba, who hosted the party with his wife, Sabrina Elba, grabbed a microphone to wish Donatella Versace a happy birthday. (Five days belated, but who’s counting?)

Benedict Cumberbatch conferred with his fellow Marvel-movie hero, Chadwick Boseman from “Black Panther,” while Alicia Vikander sat in a V.I.P. pod with Gemma Chan, Riley Keough, Chloë Grace Moretz and Prabal Gurung.

Lena Waithe entered, stage left, in a vintage “Waiting to Exhale” T-shirt. Robyn tried to bum cigarettes, Justin Theroux jousted with photographers by taking pictures of them, and Celine Dion danced like it was all coming back to her now.

Mr. Elba was on a tear. He grabbed the mic again to announce that he is “good at everything,” his new rap name is “Slim Biggie,” and Michael B. Jordan “is one of the best actors in the world.”

Just after 2 a.m., Karlie Kloss and her husband, Josh Kushner, sauntered in as Emily Ratajkowski was leaving. Huma Abedin posed for pictures, somewhat coquettishly, while Tracee Ellis Ross bewildered Andrew Garfield by greeting him in a mock-Cockney accent.

It wasn’t long after that Ms. Perry came barreling past, in her cheeseburger outfit. All three parties also had Hamish Bowles in common, the Vogue editor who was instrumental in planning this year’s camp-themed gala.

“My favorite moment? It was my placement,” he said, pronouncing it in the French manner. “It was between Dame Glenda Jackson and Kim Kardashian West. That tells you everything there is to know about this evening.”