It's a good thing Kristen Stewart was cast as a lead in Clea DuVall's Happiest Season, because the out actress would have been "so jealous and very excited" to see the movie come together without her.

Stewart stars alongside Mackenzie Davis (Black Mirror's beloved "San Junipero" episode) in the forthcoming film, a holiday-themed lesbian rom-com co-written by DuVall and Mary Holland. (It's also directed by DuVall, who is a lesbian herself.) The movie was filmed on location in Pittsburgh, Pennsylvania, and shooting wrapped right before the COVID-19 pandemic hit.

Speaking to NewNowNext on the set of Happiest Season in late February, Stewart said she loved the script instantly. "It felt like a huge relief," she admitted. "It didn't feel obliged to be overwrought, but it's so tender, and I think with a Christmas movie, knowing that everything's going to be okay allows for you to... I don't want to be too specific."

She noted that a Christmas movie about a lesbian couple like Happiest Season "doesn't exist yet," and she's not wrong. In the film, Stewart plays Abby, a proud queer woman who is planning to propose to her girlfriend, Harper (Davis' character). Chaos ensues when Abby goes home with Harper for the holidays, only to realize that her GF isn't out to her WASP-y, traditional family.

Davis (L) and Stewart in Happiest Season.

Davis added that there is "no villain" in Happiest Season. "[Harper's parents] live in a very WASP-y, rich environment, and anything that's out of that sort of paradigm feels scary and too foreign to them to accept immediately. But once they're confronted with it, I think they handle it well," she explained. She likened her character's family to politicians who "need to have a gay child" to feel compelled to support LGBTQ equality: "You're like, 'I'm happy you came around to it, [but] it's so weird that you needed to be related to someone to have just the basic shred of empathy that most people are able to muster up.' They need to be exposed to it, and they haven't been exposed yet."

What drew Davis and Stewart to Happiest Season? Davis also fell in love with DuVall and Holland's writing. "It feels purposeful and important and urgent," she explained. "I felt like the script had such a distinct voice. Clea and Mary, who wrote the script, they just have such distinct comedic sensibilities. It's so funny."

And Stewart knew she had to be involved with such a groundbreaking project: "[The movie] doesn't shy away from what it is, which is a really beautiful love story and a coming-out story about two women. ... I fucking belong here."

Happiest Season premieres November 25 on Hulu.