Did Work Drive Kate Winslet, Sam Mendes Apart?

Sources close to the couple say marriage suffered after "Revolutionary Road."

LONDON, March 16, 2010 — -- A day after Oscar-winner Kate Winslet and her director-husband Sam Mendes announced plans to divorce sources close to the couple said the marriage began to suffer after the two worked together on "Revolutionary Road," a film about a marriage torn asunder.

A source close to Winslet and Mendes told British tabloid The Daily Mail that "Things were extremely rough to say the least recently. Things went downhill after 'Revolutionary Road.'"

In "Revolutionary Road," Winslet played a bored suburban housewife married to Leonardo DiCaprio. Mendes directed the two, who first starred together in "Titanic," in a racy sex scene.

Upon winning a Golden Globe for her role in "Revolutionary Road," Winslet thanked Mendes, whom she affectionately called "babe."

"Thank you for directing this film, babe, and thank you for killing us every single day and really enjoying us actually being in such horrific pain," she said. "But I can honestly say with my hand on my heart that I loved every second of working with you, and it's made me love you more."

At the time of the film's release, Mendes told the British newspaper The Times, "We are very happy, but obviously there is a cathartic aspect of making a movie about a bad marriage. Put it this way: The last thing you want to do when making a fight film is to go home and have a fight. So here is the opportunity for getting it out without having to live it."

Friends Say Couple's Marriage Lost Its Spark

The couple reportedly split earlier this year, but a London law firm released a statement only Monday announcing the pending divorce, saying it is "entirely amicable and is by mutual agreement."

"Both parties are fully committed to the future joint parenting of their children," the statement said.

Before meeting Winslet, Mendes was a self-described workaholic, winning an Academy Award for his 1999 directorial debut, "American Beauty." "I don't think I had supper at home for four years," he said.

Since marrying in 2003, the couple focused on raising their son, Joe, and Mia, Winslet's daughter from her first marriage to British director Jim Threapleton. But recently, Mendes began devoting more time to work, directing a second film, "Away We Go," and signing up to direct the next James Bond film.

He is also said to be in the process of developing adaptations of the British classic Middlemarch, and the Joseph O'Neill novel Netherland, and working on a new touring season with his theater company, the Bridge Project.

A friend of Mendes told The Daily Mail that "He became bored working on his latest theatrical project, and he took that boredom home with him. And that led to the spark being taken out of their marriage."

The source added, "Kate is devastated. She thought their marriage was forever and now she has two children from two marriages and both are not living with their fathers."

As speculation continues over what led to the end of one of Hollywood's highest-profile marriages, one of the couple's friends dismissed talk of third-party involvement. She told U.K. newspaper The Telegraph, "There really is no story," adding that the split was "perfectly amicable."

Mendes and Winslet, both Oscar winners, were not seen together at this year's Academy Awards.

Before her 2009 win, Winslet had been nominated five times, for roles in "Titanic," "Sense and Sensibility," "Iris," "Eternal Sunshine of the Spotless Mind" and "Little Children."

Famously superstitious, Winslet and Mendes vowed never to fly on the same plane together after Sept. 11, 2001. Mendes nearly boarded American Airlines flight 77 that morning, the plane that was crashed into the Pentagon.

The shapely Winslet, who is often asked about body image, was seen over the weekend in Mexico wearing a bikini -- without Mendes.

Mendes is said to have moved into the apartment just below the couple's New York home.