Kate Bosworth and Justin Long Spark Engagement Rumors at Vanity Fair Oscars 2023 After-Party

And the award for most eye-catching jewelry at an Oscars event goes to....

Kate Bosworth sparked engagement rumors with Justin Long when she arrived to the Vanity Fair Oscars 2023 after-party sporting a sparkling diamond ring.

The couple stepped out for the soirée in glamorous styles, with Justin wearing a sharp suit and Kate donning a Monique Lhuillier strapless gown—with the diamond ring placed on that finger.

Justin and Kate first sparked romance rumors nearly two years ago, when she gushed about the 44-year-old after they finished filming a movie together in Fayetteville, Ark.

"There are some movie experiences when you learn a lotttttt about another person. Well, we just wrapped one of those," Kate wrote on Instagram in May 2021. "Holy moly @justinlong you are a truly spectacular / fun / funny / kind / rare / thoughtful / totally. fckn. rad human being."

As he wrote in response, "I'm going to say even nicer things about you publicly because people should know what a rare gem you are - all the things you said about me but a little bit (or a lot) more. It was a true joy to be in your glow."

Later, in April 2022, they were spotting making out while on the beach in Kauai, Hawaii.

The pair then spent Thanksgiving together. And Kate was sure to ring in the holiday by posting a message of gratitude for Justin's "warmth and safety and that bright beautiful ever glow."

Reflecting on her sweet words, Justin said during a November appearance on Today, "Well, she makes me glow. This is making me blush because it's so… It's the best best. It's so nice to talk about."

The pair were certainly glowing together on the Vanity Fair red carpet. To see more stars who stepped out for the March 12 event, keep reading...

In Bach Mai

In Zuhair Murad

In custom Zac Posen

In custom Maison Margiela

Sophie in Louis Vuitton

In Feben

Rita in Weiderhoeft

In Donna Karan

In Robert Wun

In Gabriela Hearst

In custom Chrome Hearts

In Dolce & Gabbana

In Jean Paul Gaultier 

In Balmain

In custom Saint Laurent and YSL Beauty

In Celine

Jodie in Gucci

In Valentino Haute Couture

In Louis Vuitton

In Stella McCartney

In Zuhair Murad

Kate in Monique Lhuillier

In Alexander McQueen

In Celine and YSL Beauty

Dwayne with a Vacheron Constantin watch, Gabrielle in Ralph Lauren

For the latest breaking news updates, click here to download the E! News App