AceShowbiz -

Jessica Biel and Justin Timberlake have just made their first appearance at the Costume Institute Gala as an engaged couple. The former "7th Heaven" beauty and her "SexyBack" singer fiance happily posed for the press together when arriving at the red carpet outside the Metropolitan Museum of Art in New York City on Monday, May 7.

Showing off a simple yet stunning style, 30-year-old Biel rocked an ivory double stretch satin deep-V gown with cascading jade green stones by Prada that she paired with Lorraine Schwartz jewelry. Her 31-year-old fiancee, in the meantime, looked dapper in a black Tom Ford tuxedo with a satin shawl lapel, evening shirt, satin bowtie, cufflinks and leather "Chelsea" boots.

This is not the first time Biel and Timberlake came to the MET Ball as a couple though. The twosome had attended the benefit event together twice before, in 2009 and 2010. This year, they came to help celebrate the opening of the "Schiaparelli and Prada: Impossible Conversations" exhibition.

Biel and Timberlake also weren't the only famous couple putting a united front at the event. Kristen Bell and Dax Shepard, Claire Danes and Hugh Dancy, Amy Poehler and Will Arnett, as well as supermodel Gisele Bundchen and her NFL star husband Tom Brady also walked arm-in-arm on the red carpet on Monday evening.

Bell and Shepard were clad in Tommy Hilfiger with Bell wearing an orange crinkle silk chiffon gown with crisscross halter neckline and Shepard rocking a black peak lapel two button tuxedo. Danes, in the meantime, opted to go with a white wrap-style J.Mendel dress, while her husband was decked in Prada's navy kid mohair one-button tuxedo with faille silk shawl collar.

Poehler herself went with a Fotini dress, Jimmy Choo shoes, and Tiffany & Co jewels, while Bundchen looked stunning in a Givenchy dress and shoes that she paired with David Yurman jewelry. The supermodel's husband, Brady, slipped on a Tom Ford tuxedo and set his hair in a semi-faux hawk.