Karlie Kloss' best accessory for the Met Gala 2023? Her growing baby bump.

The supermodel announced she's pregnant with her second child while walking the red carpet at the Metropolitan Museum of Art in NYC on May 1. (See every star on the Met Gala 2023 red carpet here.)

The 30-year-old showed off her growing tummy in a body-hugging black long-sleeved, floor-length dress by Loewe, with nods to the evening's theme of Karl Lagerfeld: A Line of Beauty. Kloss' sleek look featured gold details around the neck and waist, which she complimented with long strands of pearls draped around the same areas. She completed the ensemble with rings and earrings by Garrard.

As for her glam, the former Project Runway host pulled her brunette hair back in a long ponytail.

Kloss' husband Josh Kushner was by her side for the annual fashion fanfare, which is co-chaired this year by Michaela Coel, Penélope Cruz, Roger Federer and Dua Lipa, alongside Anna Wintour. The businessman looked handsome in a classic black tuxedo and bow tie while posing for pics with his other half.

Kloss and Kushner welcomed son Levi in March 2021. Last year, Kloss got emotional opening up about motherhood, calling it "the greatest joy I never knew."

"I just had this moment of like, ‘Wow, every woman who has a child, every parent goes through this,'" she Today in April 2022. "It's just the most profound experience that I had no idea until having a kid."

One month earlier, Kloss shared a sweet tribute to Levi on his first birthday. "In the blink of an eye my baby is 1," she wrote on Instagram. "Becoming a mama has been the greatest joy of my life, I have never grown more as an individual or loved more deeply. Levi, thank you for choosing us. @joshuakushner and I love you more than we can ever express. Xoxo."

Keep scrolling to see all the celebrity couples enjoying date night on the Met Gala red carpet.

Rihanna in Valentino and Bulgari jewelry, A$AP Rocky in Gucci and Boucheron jewelry

Serena in Gucci

In Valentino; Priyanka in Bulgari jewelry

Karlie in Loewe

Suki in Fendi; Robert in Dior Men by Kim Jones

In Prada

In Valentino

In Prabal Gurung

Nicole in Chanel

Salma in Gucci

Brooklyn in Chanel

Jeremy in Prada

Viola in Valentino

Kerry in Michael Kors

Hugh in Zegna, Deborra-Lee in Tom Ford

In Calvin Klein

In Tom Ford

In Alexander McQueen

James in Dunhill

In Roisin Pierce

And visit E! Online's 2023 Met Gala page for every photo and must-see moment from fashion's biggest night.