Call it the straw that broke the camel's back. Six months after her husband Rupert Sanders was caught cheating with Kristen Stewart, Liberty Ross decided to file divorce. But a source tells Us Weekly that the British model, 34, had been unhappy in her ten year marriage long before the headline-making fling.
"She wasn't very happy, even before all this happened," the source tells Us. "Rupert put a lot of pressure on her to change her life for him and they moved to L.A. for him. She was such a big deal in England -- a bigger deal than him even."
Ross, who was previously a top fashion model in London, opened up to YOU magazine in July 2012 about how "isolating" it felt to move to Hollywood with her husband and give up her career. "I went from the glamour of working with Karl Lagerfeld and John Galliano to living on an isolated hilltop, with my husband gone most of the time," Ross said. "I romanticized domesticity for a while, and loved having a shopping list of groceries stuck to the fridge for the first time. But moving here and starting a life all over again was a lot harder than I had anticipated."
The Snow White and the Huntsman director married Ross in 2002 and they have daughter Skyla, 7, and son Tennyson, 5, together. "They did love each other," the source explains, "but I think she was so unhappy and he was putting himself first [that] it was taking its toll."
In exclusive Us Weekly photos, Sanders, 42, was caught making out with his Snow White and the Huntsman actress Stewart, 22, in mid-July. In the divorce papers filed Jan. 25, Ross asks for joint custody of their kids, spousal support and attorney's fees. Sanders is also seeking joint custody, but it not asking for spousal support.
"They gave it a shot for the kids, [but] she was just so angry," a second insider told Us of Sander's tryst with Stewart. "She's the kind of person who wouldn't really ever get over it."
But Sanders ultimately agreed with the decision to end their marriage after a decade together. A source said that "it was definitely mutual."
This article originally appeared on Usmagazine.com: Liberty Ross Asks Rupert Sanders for a Divorce: What Went Wrong