It may not have been the “Happiest Season” for the cast of the new Hulu holiday rom-com.

In a new interview, Aubrey Plaza revealed COVID-19 hit the set of the Kristen Stewart-led LGBTQ Christmas movie in late February when they were filming.

“Yes, right before COVID, in fact, COVID was on our set. Kristen got sick, but we didn’t know,” Plaza, 36, said on “The Late Show With Stephen Colbert” last week.

Plaza added that a lot of people on the set got sick around that time and no one thought anything of it.

“It was the last week of February so people were starting, it was like that zone where people were starting to talk about coronavirus, but people were laughing about it,” she said. “No one understood how serious it was. But a bunch of people on our set got sick. I didn’t, thank god.”

Reps for Hulu and Stewart did not immediately return Page Six’s request for comment.

The film — which also stars Dan Levy, Mackenzie Davis, Mary Steenburgen, Victor Garber and Alison Brie — hit the streaming service on Nov. 25.