Hugh Grant has revealed why he isn’t married yet.

During his first ever guest appearance on “The Howard Stern Show” on Wednesday, the 55-year-old English actor admitted that he doesn’t believe in marriage.

“I can see the lovely aspect [of marriage] if you marry exactly the right person — your best friend and it's cozy and it's lovely. But, people make so many mistakes," Grant told Stern (via E! News). "Do I think human beings are meant to be in 40-year-long monogamous, faithful, relationships? No, No, No. Whoever said they were? Only the bible or something. No one ever said that was a good idea."

The Golden Globe-winning actor added that “there's something unromantic about marriage.” When asked what it is, he said: “You're closing yourself off.”

While Grant doesn’t believe in marriage, he thinks that extramarital affairs might actually help marriages.

In the new British-French dramedy film “Florence Foster Jenkins,” Grant plays a character that has a mistress, and the actor admitted to Stern that he “likes” it.

"I always admire the French and the Italians who are very devoted to their marriages," Grant said. "They take them extremely seriously, but it is understood that there might be other visitors at 5 o'clock in the afternoon. You just never boast about. They never say anything, but that's what keeps marriages together."

Although never married, Grant has four children. He has two kids with Swedish television producer Anna Eberstein, and another two with Tinglan Hong — a receptionist at a Chinese restaurant in London.

Although Grant’s eldest child, Tabitha, was not planned, Grant revealed to The Guardian back in March 2012 that he likes his daughter "very much." "I'm absolutely thrilled to have had her — I really am. And I feel a better person," he said at the time.

The following month, Grant appeared on "The Ellen DeGeneres Show" and said: "Everyone was right all these years, saying, 'Hugh, why don't you have some children? It changes your life.' Now that I have one, it is life-changing. I recommend it. Get some!"

“Florence Foster Jenkins,” which also stars Meryl Streep, Simon Helberg, Rebecca Ferguson and Nina Arianda, opens in U.S. theaters on Friday, Aug. 12.

Hugh Grant Hugh Grant admitted during his first guest appearance on “The Howard Stern Show" that he doesn’t believe in marriage. Pictured: Grant attends the Hollywood Foreign Press Association's Grants Banquet at the Beverly Wilshire Four Seasons Hotel on August 4, 2016 in Beverly Hills, Calif. Photo: Getty Images/Frazer Harrison