Speaking to WHO's sister site PEOPLE, Nicole realised Keith was The One when he surprised her on her birthday at her doorstep in New York at 5am holding gardenias.
“That is when I went, ‘This is the man I hope I get to marry,’” she told the publication.
The two then went on a trip to Woodstock, New York, and the Moulin Rouge! star admitted: “It was pretty intense. I believed by that point he was the love of my life. Maybe that’s because I am deeply romantic, or I’m an actress, or I have strong faith as well, but I just believed, ‘Oh, okay, here he is.’”
By June 2006, the couple were husband and wife - they tied the knot in a romantic ceremony in Manly, Sydney.
In 2008, the couple welcomed their first child, Sunday Rose and two years later, Faith Margaret joined the family.
“I wish I could have met [Keith] much earlier and had way more children with him, but I didn’t. I mean, if I could have had two more children with him, that would have been just glorious,” the actress, who also shares adoptive children Isabella and Connor Cruise with her ex-husband, admitted to Vogue.
Over the years the couple have supported one another in good and bad times.
In 2014, Nicole’s father passed away and the actress revealed just how much Keith helped her during her grief.
“He has been so good to me for nine years, but for the last sort of month—which has been a really tough time for me—when you have your partner who just literally carries you through a tough time, he’s been amazing to me,” she said.
“To have my husband to step up in that way, it makes me cry. He’s amazing. I will keep him. I’ll do anything for that man.”
Even with hectic work schedules and kids to look after, Nicole and Keith continue to make each other a priority whether they're on a red carpet or stuck at home during lockdown.
"Someone said one time, 'If your marriage isn't your priority, you're not married,' and I thought, for me that's so true," Keith said during a Country Radio Seminar Q&A session.
"So as long as I keep her as a priority, everything else sort of seems to work. And when I don't keep it as a priority, it's … Jenga."