PHOTO: BENGT NYMAN/CC BY-SA 4.0/WIKIMEDIA COMMONS

The King of Sweden has shared the secret to a happy marriage.

King Carl XVI Gustaf revealed his best (and surprising) relationship advice in the documentary film “Kungen”, which opens in theaters on February 24.

His Majesty said the secret to his happy 47-year marriage to Queen Silvia is – separate bathrooms.

In the film, Karin af Klintberg asks the monarch for personal marriage advice, to which he replies: “Separate bathrooms.”

King Carl Gustaf and Queen Silvia live in Drottningholm Castle, their private residence near Stockholm.

Klintberg shared her thoughts on the king’s advice as she spoke Today’s newssays the monarch gave a very practical answer.

She said: “He gave a correct answer, and I think that’s pretty good relationship advice, ie keeping the private spheres, not fumbling and cutting nails in front of each other, although of course it’s impossible for many. I also thought I was asking another, perhaps more psychological, question, but the King seems very practical about things and language!

The film was shot in connection with the golden jubilee year of King Carl Gustaf, who celebrates his milestone on September 15. The celebration of the golden jubilee takes place throughout 2023.

The king and queen Silvia were married on 19 June 1976 in Stockholm’s cathedral after meeting at the 1972 Munich Summer Olympics.

It was the first wedding of a reigning monarch since 1797.

The couple has three children: Crown Princess Victoria (b. 1977), Prince Carl Philip (b. 1979) and Princess Madeleine (b. 1982). Through their children, they also have eight grandchildren: Princess Estelle and Prince Oscar from Crown Princess Victoria’s marriage to Prince Daniel; Prince Alexander, Prince Gabriel and Prince Julian from Prince Carl Philip’s marriage to Princess Sofia; and Princess Leonore, Prince Nicolas and Princess Adrienne from Princess Madeleine’s marriage to Chris O’Neill.