Nicole Kidman revealed her secret to her 'successful' marriage just months before shock Keith Urban split

Nicole Kidman's secret to a long-lasting marriage has resurfaced, as she shared some advice earlier this year.

The 58-year-old actress and long-time husband, Keith Urban, 57, have reportedly split after almost 20 years together.

News broke on Monday (29 September) as multiple outlets reported that the couple called it quits months ago and have even been living separately 'since the beginning of summer'.

But judging by the Babygirl star's comments in January, you wouldn't have seen the split coming.

Kidman has been involved in a number of steamy scenes in films over the years, though she has previously explained that Urban didn't care for them.

"He really doesn't know what's going on on the set, he's got his own career that he's completely absorbed in," she told E! News in 2021.

Nicole Kidman and Keith Urban were spotted together at a FIFA Club World Cup game this summer (Richard Pelham/Getty Images)

But the split with the country music star seems to be going ahead, with him even moving out of the family home to live elsewhere in Nashville, according to TMZ.

Apparently, Kidman didn't want the separation and 'has been trying to save the marriage', with the reason for the separation still unclear.

Rewind the clock to the start of 2025 and Kidman appeared to be smitten with the father of two of her children, telling W Magazine the 'secret' they had to maintaining a relationship for so long.

When asked if she sang in the shower, she revealed: "I do, I also hear Keith singing in the shower, and I'll hear his new songs forming."

"We have a double shower," Kidman said, claiming: "The double-headed shower: key to a successful marriage. Separate commodes and a double-headed shower!"

Kidman revealed at the time that it's the little things that make a relationship work (Taylor Hill/WireImage)

The couple first met at the G'Day USA gala in Los Angeles in 2005, before tying the knot in Sydney in June 2006 and have two children together, Sunday Rose, 17, and Faith Margaret, 14.

Kidman, who previously called Urban the 'love of her life', added that there was another secret to their relationship in a 2018 interview with People: "I think it's knowing that you have to keep contributing to what we call the 'us.' You go, 'Does this work for us?'"

The pair also still asked each other out on dates, as she told the outlet last year: "I like being asked out, which he still does."

Kidman went on to add: "I'm open [to everything]. I like not knowing where he’s going to take me. Surprise me, baby!"

Urban also claimed in a 2016 CBS News interview: "Meeting her and getting married wasn't life-changing, it was life-beginning."