Country singer Keith Urban has ruled out any talk of a duet with his actress wife Nicole Kidman - because the star couple have a pact to stay out of one another's careers. Kidman has previously demonstrated her vocal talent in musical Moulin Rouge! and collaborated with British pop star Robbie Williams for the hit single Somethin' Stupid in 2001. But Urban - who dedicated his Best Country Album gong at the 2007 Australian Recording Industry Association (Aria) Awards on Sunday (28Oct07) to his beloved wife - insists he has no desire to mix business with pleasure anytime soon. He says, "(The album) would not exist without my wife, she was the inspiration for it. She is very prevalent in most of the songs. "(But) I promise not to act as well, so it's a fair deal."