Ben Stiller's co-star in Greenberg, Greta Gerwig has joined Ivan Reitman's untitled comedy formerly known as Friends with Benefits, starring opposite Natalie Portman and Ashton Kutcher. Kevin Kline, Ophelia Lovibond and Ben Lawson have also been added to the cast, according to Variety.
The film centers of the question of whether two long-term friends can have a purely sexual relationship without falling in love.
Gerwig will play a brainy friend of Portman's character who is the first to recognize signs that Kutcher's character has become smitten with her friend. Reitman is directing from Elizabeth Meriwether's script.
Paramount has set a Jan. 7 release.