Tina Fey and Jason Bateman called mutual friends when they learned they would co-star as siblings in the drama-infused comedy "This Is Where I Leave You," just to do a little reconnaissance on each other.

"We had never worked together," Fey said. "Well, we owned a restaurant together for 10 years. We owned an Arby's."

"But that's not really work," shot back Bateman. "That is pure pleasure."

And with that sibling-like familiarity, Fey and Bateman, two of the most popular comic actors of their generation, banter on for minutes - their way of promoting the Warner Bros. film that opens in U.S. theaters on Friday.

They play Wendy and Judd, the close middle siblings of the Altman family, brought together by the death of their father and asked by their mother to follow the Jewish ritual of "sitting shiva" for the seven days of mourning.

Judd has found his wife cheating on him with his womanizing boss and has only shared the news with Wendy, herself troubled by a lifeless marriage to a workaholic husband.

Jane Fonda plays the mother, Hilary, a vivacious, breast-enhanced, best-selling author who overshares her children's lives with readers. Fonda jumped at the chance to play a woman who is "sassy and still has some libido going for her."

Rounding out the clan are the eldest, Paul (Corey Stoll), who has stayed to run the family business and is struggling to conceive a child with his wife, and, the youngest, wild child Phillip (Adam Driver).

Phillip may bring home a much older girlfriend but acts like an adolescent, such as when he repeatedly touches the private parts of the young rabbi and childhood friend Boner (Ben Schwartz).

As the Altmans sit in a row greeting mourners, all the siblings' angst over their messy adult lives comes pouring out.

"ANY SCRIPTED LINES TODAY?"

"Rare is the family that doesn't have crazy dynamics," said Shawn Levy, who directed the film based on the best-selling book by Jonathan Tropper.

"Most of us can relate to siblings who drive us nuts but who also love us fiercely and parents who fail to live up to our childhood idealizations of them."

Levy, who has directed "Night at the Museum" movies, said he always allows for improvisation and that Fey and Bateman are "as good as it gets" at coming up with ideas.

"They don't do silliness funny, they do grounded funny, and so that told me they would mesh well," Levy said.

Fey not only improvised her own lines, he said, but offered up lines to other actors, even insults of herself. "Nobody else working would do that," Levy said.

Fonda, who claims to have little talent for comedic improvisation, said she was in awe of the cast's dexterity, particularly with the unscripted moments.

But one day, according to Fey, Fonda turned to Schwartz and asked: "Will you be saying any of the scripted lines today?"

(Editing by Eric Kelsey and Leslie Adler)