Saoirse Ronan’s longtime partner Jack Lowden shared an intimate snap of the couple on Instagram on December 31, New Year’s Eve.

“NYE," Lowden captioned on his post.

The Scottish actor added “Lan May yer Lum Reek,” an old Scottish saying that translates to “Long may your chimney smoke.”

“Be good, be bad, but fannies we are all,” Lowden said, adding a heart emoji as well as a Scottish flag and Irish flag.

Lowden’s public Instagram post, which has racked up more than 21k likes, features Ronan sporting a chic short hair-do and a black turtleneck while dabbing makeup from Irish brand Sculpted.

Among the many commenters on the post were Ronan's "Foe" co-star, Irish actor Paul Mescal.

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A post shared by Jack Lowden (@jack.lowden)

Ronan, who was born in New York and raised in Co Carlow, and Lowden, who was born in Essex and raised in the Scottish village of Oxton, tend to keep their relationship pretty low-key.

The talented duo first met while filming the 2018 movie "Mary Queen of Scots." Ronan starred in the titular role, while Lowden featured as her on-screen husband Henry Stuart, Lord Darnley.

The two went on to establish Arcade Pictures, an independent film and television production company, alongside Dominic Norris.

Ronan stars in the production company's film "The Outrun," which is due to premiere at the 2024 Sundance Film Festival and will be screened at the 74th Berlin International Film Festival in the Panorama section in February.

In February last year, Lowden told Esquire it was a "great adventure" working with Ronan on the film through their production company.

"We want to only do stuff we believe in, so we’ve not set any specific parameters around that," Lowden said.

"But Saoirse and I both have a fascination with the countries we’re from, so we’re always going to have an eye on Irish and Scottish stuff because we’re both so obsessed with it."

He added: "... with Saoirse, it’s great to work with my best friend and one of my favorite actors.

"I get her perspective on things, she’s a brilliant creative mind, we have similar tastes and then different tastes, which is great."

Engagement rumors began to swirl after Ronan was spotted with a  diamond ring on her finger back in October, though neither has confirmed an engagement.