A topless Sienna Miller was spotted kissing and canoodling with married "Brothers & Sisters" star Balthazar Getty in Italy on Friday, but a source close to the star tells Usmagazine.com that "Sienna is not a homewrecker."

Getty, 33, welcomed his fourth child with wife Rosetta in 2007, but the source insists "it’s been over with him and his wife for some time. I believe he’ll be making an announcement shortly.”

Miller, 26, has been quietly dating Getty for "at least two months," a source told People magazine.

Click here to see a picture of a topless Miller and Getty

Getty, who has a tattoo of his wife's name on his chest, married Rosetta in May 2000.

"It's humiliating," a friend told People. "Rosetta left the country to protect the kids, and he continues to see Sienna publicly."

Miller, who recently split with actor Rhys Ifans and once dated Jude Law, told the Times of London last month that "my life is privileged. And it's exactly where I'm supposed to be. I make decisions. I take responsibility for them."

She also admitted that she experimented with girls while at boarding school. "We'd have the odd snog together," she said. "It wasn't all the time, but, you know, who hasn't dabbled?"

Click here to read more from USmagazine.com

Click here to read more at People.com

Click here to read Miller's interview with the Times of London