Keira Knightley says her marriage will only survive if her husband follows one strict rule

Relationships can take a lot of work, and Keira Knightley has shared the secret she says helps her marriage to 'survive'.

The star, who is starring Netflix's upcoming thriller show, Black Doves, has been married to Klaxons musician, James Righton, since 2013, and the couple are parents to two daughters together, Edie, nine, and five-year-old Delilah.

And many couples will know that Christmas can be a stressful time, with bickering over who is doing what with the cooking, forgetting to buy things, and pulling the short straw to see who is putting up the decorations.

However, Pirates Of The Caribbean actor Keira says she swears by one strict rule - particularly over the festive season.

Keira Knightley and James Righton have been married since 2013 (Pascal Le Segretain/Getty Images)

On Thursday (6 December), she told Nick Grimshaw on BBC Radio 4 that 'divorce' would be on the cards if James and his 'OCD' behaviours spread from one room in the house.

Keira revealed that she doesn't do any of the cooking over Christmas, and that James is a whizz in the kitchen, however, she says he is very particular when it comes to his way of doing things.

As per MailOnline, she joked: "He's the cook! he's a good cook. He loves food, he's a good cook and he's also a little bit OCD so as long as the OCD stays in the kitchen, then the marriage survives!

"He's allowed to be as OCD as he likes in the kitchen but it's not allowed to come out of the kitchen! But that does mean Christmas dinner will be very very good."

How's that for a silver lining?

Nick replied saying it was good to set limits when it comes to relationships, with Keira agreeing: "We have found like as far as trying to keep a relationship, you know OK for a while, if one person does have a bit of OCD, you have to give them places where it's allowed.

According to Keira, James is allowed to keep his 'OCD' behaviours in the kitchen - but nowhere else in the house (Pascal Le Segretain/Getty Images)

"And then places where it's not allowed! So I feel like the kitchen is a good place for OCD."

She then joked that if it 'comes into the living room', then she's 'not happy', adding: Divorce! Unfortunately."

Though, luckily for James, she was laughing when she said that.

As well as starring in Black Doves, Keira is also listed as an executive producer on the Netflix show, as per Tudum.

She'd previously revealed she no longer accepts jobs abroad thanks to family life.

"I couldn't go job to job abroad now," the Bend it Like Beckham star told The Times. "It wouldn't be in any way fair on them, and I wouldn't want to.

"I've chosen to have children, I want to bring them up, so I've had to take a major step back."