Alison Brie, Aubrey Plaza, Victor Garber, Dan Levy and Mary Steenburgen have been cast in “Happiest Season,” a romantic comedy starring Kristen Stewart and Mackenzie Davis.

The TriStar Pictures film, from director Clea DuVall, will debut in theaters on Nov. 20. “Happiest Season” follows Stewart’s character, who is planning to propose to her girlfriend (Davis) while at her family’s annual holiday party. She then discovers her partner hasn’t yet come out to her conservative parents (portrayed by Steenburgen and Garber).

Also joining the cast are Ana Gasteyer, Burl Moseley, Sarayu Blue and Jake McDorman.

Marty Bowen and Isaac Klausner will produce the film, while Jonathan McCoy and Wyck Godfrey will serve as executive producers. It will be shot on location in Pittsburgh, Pa.

TriStar Pictures will handle worldwide distribution, outside of the United Kingdom and Canada, which will be managed by eOne.

Steenburgen is repped by UTA, Management 360 and Gang Tyre. Garber is repped by Lou Coulson Associates, Oscars Abrams Zimel & Associates and Industry Entertainment. Brie is repped by Rise Management, WME and A.J. Brandenstein at Sloane, Offer, Weber & Dern. Plaza is repped by MGMT, CAA and Schreck Rose Dapello Adams Berlin & Dunham. Levy is repped by WME, Great North Artists Management, MGMT Entertainment and Morris Yorn Barnes Levine Krintzman Rubenstein Kohner & Gellman.