"Fifty Shades of Grey" star Marcia Gay Harden opened up about filming the adaptation of the erotic best-selling novel and how she prepared for her role in a recent interview.

The Oscar winner, who plays Dr. Grace Trevelyan Grey in the upcoming movie, told Entertainment Weekly Radio's TV Editors Hour that she "shame-read" the book in preparation for her role as the mother of kinky billion Christian Grey.

"When I was cast in it, I hadn't read it yet, so I did download it and I did shame-read it, and I don't know why, because I'm like, 'Hello, you're gonna know I'm in it anyway, so I have to read it for research," said Harden. She went on to say that her prep also included online research.

She also admitted that she did not find shooting the movie very scandalous since she was not included in any of the famous sex scenes.

"I play Mama Grey, so it's like, unless you're in the red playroom with a toy in your hand and flesh in your face, it's sort of like any other movie that you could do. I throw the dinner parties. 'Hello, let's sit down to dinner,'" she said. "But the story is so intriguing, and I think so many people have read it, and it is erotic. ... I like looking and thinking, 'Why did we anthropologically select for erotic pleasure in pain?' It's really interesting to me. And E L James has the answer."

The "Trophy Wife" star also revealed a fun fact about Jamie Dornan, the Irish actor who plays the leading role as Christian Grey.

"Behind the scenes, he'll jump into an Irish ditty, or he was singing a lot of Rita Ora," she offered. Ora plays Mia Grey in the film. "He's like [in Irish brogue], 'Oh, you got that in brain now.' We're like, 'Come back to America, because you got a scene in a minute.' 'But it's in my brain!' He's sweet."

"Fifty Shades of Grey" is set to be released on Valentine's Day in 2015.