The Pussycat Doll – who has been dating the British Formula One driver since 2008 – explained she wasn't tempted to stray when working alongside Dancing with the Stars hunk Derek Hough, as she never even considers whether other men are good looking.
She said: "I love Derek but we were like brother and sister. I never even thought he was good looking. He's not my type. But anyway, why would I need to look at anyone when I have the hottest boyfriend in the world. I don't think about other guys like that."
The brunette beauty – who recently appeared as a guest judge on Simon Cowell's talent search show The X Factor – admitted she thinks the music mogul has a soft spot for her.
She added to Britain’s News of the World: "He obviously thinks I'm the bee's knees. I was very intimidated to start with but quickly realised he's very naughty and flirtatious, and I have to keep him in line.
"I was only ever meant to be on the show for one week. But they kept on ringing me at the end of the day and asking me back."