Nicole Kidman Is Done With Duets!

Nicole Kidman is married to one of music's biggest stars and has proven her own singing chops in the films 'Moulin Rouge' and 'Nine. But Keith Urban's better half says she has no plans of following in her hubby's footsteps ... nor of joining him for a duet again anytime soon. It seems last week's performance with Keith -- a musical tribute to actor Simon Baker at the 'G'Day USA Ball' -- was just a one time thing!

"We worked on it for about a week at home in the evenings," Nicole tells Digital Spy. "It was our first collaboration and probably our last."

At least the last that other people will hear. "If we're just at home and you're playing music and hanging out then I'm fine," admits the Oscar-winning actress. "If it's professional, then I get nervous. I need to be loosened up."

Nicole, who acknowledges her husband's career is "much bigger" than hers, will appear next in the film 'Rabbit Hole,' along with Sandra Oh and Aaron Eckhart.