Naomi Watts Steps Out with Boyfriend Billy Crudup for Wellness Brand Launch Party

Araya Doheny/Getty Images for Stripes Naomi Watts Steps Out with Boyfriend Billy Crudup for Wellness Brand Launch Party

Naomi Watts and Billy Crudup stepped out in style for the launch party of Watts' new wellness brand Stripes.

The couple, both 54, both attended the event at Los Angeles' Pacific Palisades neighborhood Wednesday.

The Mulholland Drive star appropriately wore a long, vertically striped dress adorned with sparkles all over and sandals, while Crudup, of Almost Famous fame, opted for a simple light-blue buttoned shirt, dark pants and clean white sneakers at the event.

"I'm so excited to share this with my friends now and my co workers and just super thrilled," Watts said in a video from the event shared to the brand's Instagram Story on Wednesday. "Hope you enjoy."

Araya Doheny/Getty Images for Stripes Naomi Watts Steps Out with Boyfriend Billy Crudup for Wellness Brand Launch Party

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Watts and Crudup, who have been romantically linked since 2017 and made their red-carpet debut as a couple at the SAG Awards in February, posed for photos in front of a colorful backdrop made of paper hand fans and at the dinner event.

Watts has said that the decision to create Stripes was inspired by her own personal experiences with perimenopause.

"Naomi Watts shared her story tonight and it was very emotional," fitness and health expert Amanda Thebe wrote of the event in an Instagram Story Thursday, alongside a photo of her and Watts at the event. "For those of us who have had similar struggles, it's so impactful to see others being so vulnerable and honest."

Araya Doheny/Getty Images for Stripes Naomi Watts Steps Out with Boyfriend Billy Crudup for Wellness Brand Launch Party

The outing made for a rare public event for Watts and Crudup, who typically keep their relationship away from the public eye. The actor couple were first seen together in March 2017 while out for lunch in New York City. That July, a source confirmed to PEOPLE that the stars were dating.

Watts and Crudup costarred on Netflix's series Gypsy, which debuted in 2017. In February 2018, they were photographed together at the BAFTAs afterparty in London.

Watts was previously in an 11-year relationship with Liev Schreiber, which came to an end in 2016. The couple has two children together: Samuel Kai, 12, and Alexander "Sasha" Pete, 13.

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The former pair announced their split in a joint statement, saying, "Over the past few months we've come to the conclusion that the best way forward for us as a family is to separate as a couple."

Araya Doheny/Getty

Crudup, who also stars in films like 2015's Spotlight and 2019's Where'd You Go, Bernadette dated actress Mary-Louise Parker, with whom he shares 18-year-old son William Atticus, until 2003. He then dated Claire Danes from 2003 to 2006.

Watts recently revealed to PEOPLE the actress she'd want to play her in a future biopic as she hit the red carpet at the premiere for Netflix's The Watcher last Wednesday.

RELATED: Naomi Watts Says She'd Want Saoirse Ronan to Play Her in a Biopic: 'She's Fantastic'

"Oh gosh, I don't know," responded Watts, who was at first taken aback when asked, before immediately bursting out her answer. "Saoirse Ronan!" Watts, 54, said.

Although uncertain of her response at first, Watts was confident in choosing the 28-year-old talent. "Because she's fantastic in everything she does," Watts said of her decision.