"I feel like a lot of movies soften the edges of relationships and how people communicate," said the film's writer-director, Judd Apatow. "I think it's funny to show people in a very uncensored, realistic way and that's what makes me laugh. People just going off the rails."
"This is 40" has been called a sort of sequel to "Knocked Up." It features a few of the same characters, but this film focuses on Pete and Debbie, played again by Paul Rudd and Leslie Mann, respectively.
"What's wrong in a marriage is funnier than what's going well in a marriage," Mann said. "The farther you take it, the more honest you are. It just makes it that much better."
Viewers should wait for the credits featuring outtakes with Rudd, Mann and Melissa McCarthy.
"It was uncontrollable," Rudd said. "I've laughed on many sets on many takes and ruined a lot of film by laughing. But eventually I've been able to kind of pull it together. Not that day."
Apatow and Mann, who are married in real life, again hired their daughters, who were in "Knocked Up," to return for this.
"We just want them to work for us every six or seven years, so if somebody called, if I got a call from James Cameron, I would hang up on him," Apatow said.
"This is 40" is rated R. It opens Friday.