Nicole Kidman and Keith Urban's marriage secret is revealed as the "Grace of Monaco" star spilled on their nightly ritual.

The latest report from People, as shared by MailOnline, revealed the secret to Nicole Kidman and Keith Urban's marriage.

"I like lavender baths. It helps me to sleep. Keith and I have been known to take baths together, many times. It's so nice, we squeeze in!" she said.

The 47-year-old also shared some beauty secrets to the magazine: "I wear full rashies [UV sun protection shirts], a hat, sunscreen. I do not let myself get burned because I have such fair skin, but I used to burn so badly that I'd blister."

Despite being a veteran of many movies, Nicole Kidman claimed that it's always embarassing during the first day of filming, just like what she felt while shooting "Genius" with Jude Law and Colin Firth.

"I just did the first day of rehearsals for a new film, Genius, with Colin Firth and Jude Law, and I had to get up and pretend I could act. I am always embarrassed on the first day and feel like I'm bushing from head to toe," she added.

Nicole Kidman and Keith Urban's marriage has been hounded with controversies and rumors. But the death of her father seemed to have brought them closer together. Besieged by rumors about the impending Nicole Kdiman and Keith Urban divorce, he nevertheless left a scheduled gig on September 7 to be with his wife.

"I think as anyone knows, you need a partner who is there for you through the tough times, as well as the good times," she said, according to Irish Examiner. "I think when it's really, really tough and things get hard - and recently, I lost my father - and my husband was extraordinary through that."