Robert De Niro has revealed he felt like he was at a real couple's big day while filming The Big Wedding.
"The whole thing had the kind of feeling of a wedding: people were happy and having a good time," he said.
"Every wedding has tension and stress. There's always drama because everyone wants to plan everything perfectly, to get it right; to make everyone happy - but that's especially true in this movie."
Robert said the prospect of working with Diane, who plays his screen wife, drew him to the movie, the US remake of the original 2006 French film My Brother Is Getting Married.
" I liked the character and I knew Diane Keaton was going to be in and I thought that would be great," the 70-year-old added.
Diane added: "I've known Bob for many years but this was a whole new experience for both of us. There's no one else like him, and in this story we had the chance to be very playful around the whole idea of marriage and divorce and the reality that just because your marriage ends doesn't mean you ever completely let go of that affection you had for your ex... along with a whole lot of other tricky emotions.
"In the process of pretending they're back together, Don and Ellie figure out a few things about what they really want."
The Big Wedding is out on DVD and Blu-ray on October 14.