Suki Waterhouse made her red-carpet debut with longtime partner Robert Pattinson in a semi-sheer gown

• Suki Waterhouse and Robert Pattinson attended a Dior fashion show together in Egypt on Saturday.
• Waterhouse wore a semi-sheer Dior dress that coordinated with Pattinson's suit.

Suki Waterhouse and Robert Pattinson made their relationship red-carpet official after four years of dating on Saturday.

Waterhouse, 30, and Pattinson, 36, attended the Dior Fall 2023 Menswear Collection show together on Saturday in Cairo, Egypt.

The pair arrived at the show — which took place at the Great Pyramid of Giza — in coordinating Dior ensembles, according to Vogue.

Pattinson paired a white, subtly patterned suit with a brown turtleneck. Dark shoes offset his light suit.

Waterhouse's ensemble consisted of a figure-hugging slip dress with a long-sleeve, sheer overlay.

The mauve garment matched Pattinson's turtleneck, and the transparent overlay featured ruffles on the sleeves and trim, creating volume in the gown.

A bold red lip and wavy hair completed the look.

Joey Choy was Waterhouse's makeup artist, and Linnéa Nordberg was her hairstylist.

Waterhouse posted two Polaroid photos of herself from the event on Instagram, captioning the post, "Will never forgot this show, under the stars and in front of the Pyramids of Giza, one of the Seven Wonders of the World."

Pattinson and Waterhouse also posed for photos together inside of the event. They were holding hands and laughing in many of the photos.

The singer and actor have been together since 2018, but the Dior show marked their first red carpet together.

Waterhouse and Pattinson have been historically tight-lipped about their relationship.

They were first spotted together in public in 2018, as E! News reported; Pattinson had been dating FKA Twigs until 2017.

Waterhouse and Pattinson were photographed inside of a Dior party together in 2020, though they did not walk the red carpet together.

Pattinson referenced his girlfriend multiple times during his press tour for "The Batman" according to People, but he did not use Waterhouse's name.

Similarly, in a conversation with Insider's Callie Ahlgrim about her EP "Milk Teeth," Waterhouse didn't use Pattinson's name, though she did say it was a "happy, lovely" relationship.