Mackenzie Davis is in negotiations to play the lead opposite Kristen Stewart in TriStar’s romantic comedy “Happiest Season.”

The studio bought worldwide rights last to the holiday-themed “Happiest Season” from the writing team of Clea DuVall and Mary Holland. DuVall, who directed the 2016 indie “The Intervention,” is also on board to direct in what will be her directorial debut on a major studio feature. Marty Bowen and Isaac Klausner will produce with Jaclyn Huntling overseeing for Temple Hill.

“Happiest Season” centers on a young woman whose plan to propose to her girlfriend while at her family’s annual holiday party is upended when she discovers her partner has not yet come out to her conservative parents. Sony had no comment on Davis’s casting. Variety reported exclusively that Stewart had come on to the project last year.

Davis starred as the night nanny and title character in last year’s “Tully” opposite Charlize Theron. She was one of the leads in AMC’s series “Halt and Catch Fire,” and appeared in “The Martian” and “Blade Runner 2049.” She’s starring as a soldier-assassin in Tim Miller’s upcoming Terminator reboot, joining Linda Hamilton and Arnold Schwarzenegger.

Sony has not yet dated “Happiest Season.” Davis is repped by UTA and Sloane Offer. The news was first reported by the Hollywood Reporter.