Nicole Kidman thinks it's wrong to "meddle" in other people's relationships.

The Oscar-winning actress stars alongside Liev Schreiber in 'The Perfect Couple', and Nicole believes that the new mystery drama series explores a fascinating subject.

Nicole, 57 - who is married to music star Keith Urban - told 'Extra': "You never know why people stay together … I always say that about couples. That is why you don’t meddle in people’s relationships, because you actually never know what they are really doing and how they get through."

Nicole relished the experience of working with Liev on the series.

Speaking about their on-screen romance, Nicole - who was previously married to actor Tom Cruise - said: "There was great depth and heat in this relationship and it had gone through a lot over time, and how do you make it through all of those things if you do not share some sort of passion and joint narrative?"

Meanwhile, Nicole stars in 'Babygirl', the new erotic thriller film, and the actress recently admitted that she hopes it proves to be a "liberating story" for women.

The acclaimed actress confessed that she found making the movie to be a "very freeing" experience.

Nicole - who has been married to Keith since 2006 - said at the Venice Film Festival: "This is one woman’s story and this is, I hope, a very liberating story.

"It’s told by a woman, through her gaze - Halina [Reijn] wrote it and she directed it - and that’s to me what made it so unique because suddenly I was going to be in the hands of a woman with this material. It was very dear to our shared instincts and very freeing."