If there's one thing that can tempt otherwise low-key couples to show up together, it's the Met Gala. During Monday night's Catholicism-themed gathering, the red carpet saw not one, not two, but four couples who are rumored to be dating. There was Lili Reinhart and Cole Sprouse, Elon Musk and Grimes (!), Hailey Baldwin and Shawn Mendes, and Katharine McPhee and David Foster. And then there are the couples who have confirmed their relationships, but prefer to stay out of the spotlight, like Bradley Cooper and Irina Shayk, who have been publicly dating since 2015. Although the pair also welcomed a child last year, they have only been photographed together only a handful of times.

As People reported, this marks the first time they've walked the Met Gala's red carpet together. According to the outlet, they both attended 2016's tech-themed Met Gala, but refrained from walking together: Cooper appeared with director David O. Russell, while Shayk came by herself. This year, the couple showed up looking subtly on-theme. While Cooper opted for a Tom Ford tux, according to Us Weekly, Shayk dazzled in a gold Atelier Versace gown with a crystal-studded bodice, a train of feather-like pleats, and a matching gold choker. The magazine also noted a "massive ring" on the model's left ring finger, adding that engagement rumors had been floating around since she debuted the same emerald-diamond ring in December 2016.

Heavenly Bodies: Fashion & The Catholic Imagination Costume Institute Gala - Arrivals

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Neither Cooper nor Shayk have publicly commented on their maybe-engagement, but that's probably because it would be off-brand for the extremely chill couple. Met Gala aside, the pair are usually photographed doing more casual hangouts, like hanging out at the beach with their daughter, Lea, chilling with Laura Dern at Sean Penn's book launch, or getting a well-rounded tan on Diane Von Furstenberg's yacht.

Related: Met Gala 2018: See What Celebrities Wore on the Red Carpet