Kate Winslet’s marriage to Sam Mendes started to go downhill two years ago, when they worked together on Revolutionary Road. “Working and living together was incredibly intense and it basically overwhelmed their relationship,” a source tells the Mirror. “Whereas Sam wanted to switch off after a long day, Kate liked to analyze every nuance of her performance. It was just too much,” leading to a trial separation last year.
Adding to the strain of working on the same film was the fact that, just afterward, the pair was separated while Mendes filmed Away We Go. “After being in each other's pockets for so long, this, ironically, also proved really difficult,” says the source, but when the two tried spending more time together last year, “it actually ended up with them both going a bit stir crazy. They are both really driven and were arguing more than ever before.” The split proves one of the Frisky's "Oscar theories"—click here to find out which one.