The 'Big Little Lies' star and the country music legend celebrated their 12 year wedding anniversary on Monday, and Nicole says there's been one little trick that has kept them from squabbling during their time together.
When they first began seeing each other, Nicole says that they started off not communicating via text because she had no idea how to, and ever since they've chosen to only speak to each other "voice-to-voice" or in person.
In an interview with Parade magazine, Nicole was asked what their secret to a long marriage is, to which she said: "Yep. We call. And that's 12 years of marriage. We have our 12-year wedding anniversary tomorrow and we've never texted. That is so not our relationship, which is interesting right? We call. We've done this since the very beginning.
"The reason it started at the beginning was because I didn't know how to text [laughs] and it just kind of worked for us. So now we don't.
"We just do voice to voice or skin to skin, as we always say."
The 50-year-old actress - who has daughters Sunday, nine, and Faith, seven, with Keith, and adopted Isabella, 25, and Connor, 23, with ex-husband Tom Cruise - says she doesn't like using her cell phone to write message to her spouse because they can be misinterpreted.
She explained: "We talk all the time and we FaceTime but we just don't text because I feel like texting can be misrepresentative at times.
"And I've had the thing where I reread texts and I'm like, 'What does that mean?' and then read it to somebody and go 'Can you interpret that?' I don't want that between my lover and I."
The 'Lion' star says that they don't really have any "secrets" to their strong marriage, and that they just "love hanging out" together.
Asked if she has any other tips, she said: "Not having secrets. We never tell anybody any advice about their relationship or think that we have a secret. We just approach it with humility and hope and just really love hanging out. I mean it's that simple. We love spending time together. We have a lot of fun together and we just choose each other. If there is one person I can hang out with, it's him and the girls and that's it. That's so much enough for me."
We're not sure we could do it ourselves, but more power to them!