Sneak peek: Robert De Niro's 'The Big Wedding'

By Bryan Alexander, USA TODAY

Posted July 23, 2012

Robert De Niro might be one of the toughest guys in Hollywood, but getting him on one knee was a surprisingly easy task.

"It took two words," says Justin Zackham, writer/director of the romantic comedy The Big Wedding, opening Oct. 26. "Susan Sarandon. She's as sexy as it gets."

Still, Sarandon realized she was witnessing something special when De Niro dropped for a proposal scene in front of Robin Williams, who plays a priest.

"When you think of (De Niro), you generally think of these tough guys like Raging Bull or Taxi Driver," Sarandon says. "This was a once-in-a-lifetime opportunity. And he did the scene in a very moving, adorable way."

In The Big Wedding, however, De Niro's character spends much of the movie pretending to be together with another woman — his ex-wife (Diane Keaton) — for their adopted son's wedding.

"They cannot stand each other and haven't seen each other for 10 years, yet they have to pretend to be a longtime happily married couple," Zackham says.

De Niro also poses as a dutiful Catholic during the wedding weekend, even agreeing to go to confession — where he quietly curses at the priest (Williams).

"The confessional scene is a big reason why the movie's rated R," Zackham says. "It's the last place his character would ever want to end up. And he makes that clear in the confession."

But he keeps up the act in an effort to reunite his family, including his daughter (Katherine Heigl) and son (Topher Grace), which has been fractured since his divorce.

"(De Niro's) character is cantankerous, he's morally questionable, but he loves his family more than anything," Zackham says.

De Niro shows some frisky new sides in the film, including an opening scene in which he and Sarandon get playful in the kitchen. "We see them on the counter, that's all I'll say," Zackham says.

When he is able to drop the charade with his ex-wife and propose to Sarandon's character, De Niro spontaneously gave her bare foot an extended kiss.

"He plays someone not at all sensitive to women's needs, but he comes around," Sarandon says. "It shows there's hope for all men."