'I had a crush on him for a long time' said the Roar singer, 28. 'It just so happens we fit together great.'
In an interview with W magazine, the curvaceous beauty also admitted she has made her peace with her divorce to Brand, 38, saying: 'everything happens for a reason.'
She added: 'It was a new fun, exciting journey. But I like how I am now, and I think all things happen for a reason.'
And the star's latest love, singer John Mayer, 36, has also had his fair share of famous partners, previously being linked to Jennifer Anniston, Taylor Swift and Jessica Simpson to name but a few.
The couple have been dating on and off for a year, but have been plagued periodically by rumours of a split. For now, at least, it seems this is a match made in showbiz heaven.
Meanwhile, back at camp Brand, the lothario has admitted he had a sexual encounter with a man in a pub toilet whilst doing a documentary back in 2002.
Speaking of the experience, he said: 'I think of myself as heterosexual but perhaps that's 'cause of the environment that I grew up in where homosexuality may have been difficult for me to express.'