Ryan Gosling, Rachel McAdams clashed while filming ‘The Notebook’

“The Notebook” is all about the love story, but during filming costars Ryan Gosling and Rachel McAdams weren’t all unicorns and butterflies with each other, according to a new interview with the movie’s director.

“Maybe I’m not supposed to tell this story, but they were really not getting along one day on set. Really not,” Nick Cassavetes told VH1 in an interview to mark the 10-year anniversary of the film’s June 25, 2004, release.

One day Gosling stopped a scene with McAdams -- a scene with 150 people in it, mind you -- for an emergency chat with his director, Cassavetes said.

The actor’s request: “‘Would you take her out of here and bring in another actress to read off camera with me? ... I can’t do it with her. I’m just not getting anything from this.’”

Ouch. At this point, former child-star Gosling had way more experience in films and TV than McAdams did, “Mean Girls” aside, but calling someone out like that on their acting ability is pretty brutal.

Cassavetes said he, his stars and a producer took it to a room where the scene partners “started screaming and yelling at each other. I walked out.”

A few minutes later -- apparently in the time it takes to smoke a cigarette -- Gosling and McAdams emerged from the room ready to work. And the show went on.

“I think Ryan respected her for standing up for her character and Rachel was happy to get that out in the open,” the director said. “The rest of the film wasn’t smooth sailing, but it was smoother sailing.”

The costars would, of course, start dating about a year after “The Notebook” hit theaters. They broke up in 2007, with a brief reconciliation in 2008.

“People do Rachel and me a disservice by assuming we were anything like the people in that movie,” Gosling told GQ a few months after the first breakup. “Rachel and my love story is a hell of a lot more romantic than that.”

Follow Christie D’Zurilla on Twitter @theCDZ and Google+. Follow the Ministry of Gossip on Twitter @LATcelebs.