The couple shared some PDA on Monday as they arrived at the Metropolitan Museum of Art for the Costume Institute Gala, putting on a dazzling display in their coordinated Valentino ensembles.
Peltz, 26, appeared to channel Marilyn Monroe from Gentlemen Prefer Blondes, hitting the red carpet in a textured sparkling pink gown with spaghetti straps and a short train. She accessorized the look with some long blush evening gloves and a pair of chandelier earrings.
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"Honestly, it was the first dress I tried on and I loved it," Peltz told Vogue of her look, as Beckham, 22, clad in a classic black tuxedo, added: "She tried this on and then I kind of... I matched it. That's how it goes."
Beckham announced his engagement to Peltz in July 2020 after they made their relationship public earlier that year in January. "Two weeks ago I asked my soulmate to marry me and she said yes xx I am the luckiest man in the world," he wrote on Instagram last summer. "I promise to be the best husband and the best daddy one day. I love you baby xx."
They also chimed in on the benefit's theme, In America. "I'm trying to make him an American right now, I don't want him to go back," Peltz gushed of her husband-to-be, with whom she lives in Los Angeles.
Be sure to check out all of PEOPLE's Met Gala coverage to get the latest news on fashion's biggest night.
This year's Met Gala kicks off a two-part exhibition with the September 13 benefit. Part one, titled In America: A Lexicon of Fashion, will debut on September 18, 2021, running until September 5, 2022. The exhibit will "celebrate The Costume Institute's 75th anniversary and explore a modern vocabulary of American fashion," according to Vogue and exhibit organizers.
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Part two, In America: An Anthology of Fashion, will open on May 5, 2022, and it "will explore the development of American fashion by presenting narratives that relate to the complex and layered histories of those spaces." Part two will also close on September 5, 2022.
The Costume Institute Gala at the Metropolitan Museum of Art was delayed from its usual scheduled date on the first Monday in May after last year's event was cancelled due to the COVID-19 pandemic. Guests are required to provide proof of vaccination and wear masks at all times, except for when drinking and eating.