How Justin Bieber Honored Wife Hailey During Met Gala After-Party Performance

She's his one love, his one heart, his one life for sure.

The Biebers celebrated their third wedding anniversary at the 2021 Met Gala, keeping it sleek in Yves Saint Laurent for the bash on Monday, Sept. 13. After posing for photos on the red carpet, Justin Bieber made sure to shower Hailey Bieber with love to give her a special and romantic night once the cameras were gone.

Stylist Maeve Reilly, who has worked with Hailey, shared a video of Justin onstage "singing to his wife on their anniversary" later in the evening. During their glamorous date night, he serenaded her with "All That Matters," singing, "You make me complete / You're all that matters to me."

Justin gave a concert both at the Met Gala itself (which got Addison Rae up off her feet) and at the Balenciaga after-party, where he performed for most of the night, a source exclusively tells E! News.

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"They set up a stage for Bieber and he arrived in a casual T-shirt and a hat," says the source. "He performed the entire night with a band and looked like he was having a blast."

Justin told the crowd he was so excited to be back in person. His set list, as the newly crowned VMAs Artist of the Year, included the fan favorites "Peaches," "Love Yourself," "Sorry," "Anyone" and "Where Are Ü Now." Photos showed him dressed in a black ski mask and all-denim suit.

The source shares, "He was very excited to be there and even gave Hailey a shoutout on the mic, saying 'Shoutout to my wife.'"

Justin shared a pic of the model on Instagram, writing, "This is the woman of my dreams." Hailey wrote on Instagram that it was a "beautiful night" all around.

The event also debuted Justin's new line with his brand Drew House, which he repped at the gala with a branded briefcase and sneakers, styled by Karla Welch. According to the insider, the Balenciaga party served popcorn and french fries with the Drew House logo, further cementing their partnership after Biebs became an ad-campaign model for Balenciaga in July.

While her husband was occupied and entertaining the crowd, Hailey hung out with the Kardashian-Jenners at the event, per the source.

Sporting a black minidress, she arrived to the after-party at the same time as pal Kendall Jenner. "They were escorted to a table front and center and were having drinks together and dancing to Justin's music," the insider dishes. "Both of them had smiles on their faces and looked like they were having fun."

Naturally, they had Kendall's 818 Tequila with them at the table.

Kim Kardashian, who sported a face-obscuring Balenciaga ensemble to the Met Gala, arrived later on with the house's creative director, Demna Gvasalia, who also walked the red carpet by her side (no, Kanye West wasn't there). "She was showing her face, had a huge smile and was getting approached left and right," the insider notes. "They said hi to Kendall and Hailey, and Kim didn't stay for long."

Though Kim didn't indulge in a drink, she mingled for a bit with Demna. "He was introducing her to several people and she was very friendly," the insider adds.

See every look from the Met Gala here.