Justin Long and Kate Bosworth attend the 2023 Vanity Fair Oscar Party Hosted By Radhika Jones at Wallis Annenberg Center for the Performing Arts on March 12, 2023 in Beverly Hills, California. (Photo by John Shearer/WireImage)

Kate Bosworth and Justin Long not only made their red carpet couples debut at the 2023 Oscars afterparty on Sunday evening, but they sparked engagement rumors in the process too.

The Blue Crush actress was photographed wearing an impressive glittering diamond ring on her ring finger, and posed at times resting her hand on Long’s chest.

For the occasion, Bosworth teamed what might be a new sparkler with a classic gown from Monique Lhuillier’s Fall/Winter 2023 collection. Evoking timeless elegance, the dress featured a black velvet bustier top with a plunging sweetheart neckline and a soft blush pink voluminous floor-length skirt. Ever the supportive partner, Long got down on the ground to help adjust Bosworth’s train for photos.

(L-R) Kate Bosworth and Justin Long attend the 2023 Vanity Fair Oscar Party Hosted By Radhika Jones at Wallis Annenberg Center for the Performing Arts on March 12, 2023 in Beverly Hills, California. (Photo by John Shearer/WireImage)

The starlet wore her signature blonde locks in a slicked back chignon with a middle part and kept her makeup minimal for a clean and eternally chic look, with just a pair of diamond earrings to complement her ring.

In keeping with Bosworth‘s polished ensemble, the He’s Just Not That Into You actor coordinated in a streamlined, classic black suit for the event.

In January, Bosworth posted a sweet homage to Long, expressing her gratitude for making her birthday so special. “You are my love and my light, my peace and my thrill,” she wrote. “Thank you for holding my hand when we sleep. Thank you for tying my shoelaces when you notice they are undone. Thank you for making me laugh so hard I have to leave the room. Thank you for showing me what love is and for making this the best birthday ever 💛 xx”

(L-R) Justin Long and Kate Bosworth attend the 2023 Vanity Fair Oscar Party Hosted By Radhika Jones at Wallis Annenberg Center for the Performing Arts on March 12, 2023 in Beverly Hills, California. (Photo by Amy Sussman/Getty Images)

The starry-eyed couple met in 2021 while filming Zach Cregger’s horror flick Barbarian in Fayetteville, Arkansas. The pair sparked romance rumors in May when Bosworth posted a heartfelt tribute to her co-star on Instagram after production wrapped. “Holy moly @justinlong you are a truly spectacular / fun / funny / kind / rare / thoughtful / totally. fckn. rad human being. 🌻,” she captioned the post.

By August, Bosworth announced her split from her husband of eight years, Michael Polish and in December, Long and Bosworth were confirmed to be a couple.

Justin Long and Kate Bosworth attending the Vanity Fair Oscar Party held at the Wallis Annenberg Center for the Performing Arts in Beverly Hills, Los Angeles, California, USA. Picture date: Sunday March 12, 2023. (Photo by Doug Peters/PA Images via Getty Images)

In conversation with comedian Fortune Feimster on a December 2021 episode of his podcast Life Is Short with Justin Long, the Accepted actor vaguely confirmed he was in a relationship, referring to an unnamed woman as his “girlfriend.”

Later, Long spoke with the Bachelor star Nick Viall on his podcast The Viall Files last April 2022, opening up about his relationship. “I was ready to be — I didn’t know it at the time — but I was ready for the one,” he said. “And the one I had met, I had found.” While wanting to keep their relationship private, he also explained that wants to “scream it from the rooftops, but I also want to be protective. It’s sacred.”

Stay tuned for updates.