Jamie Dornan says he's not shocked by the graphic sex in Fifty Shades of Grey and is ready to take on the challenge with costar Dakota Johnson

Sounds like Jamie Dornan is the right man for the job! Speaking for the first time since landing the highly coveted role as Christian Grey in the film adaptation of E.L. James' Fifty Shades of Grey, the hunky Once Upon a Time actor tells Entertainment Weekly he's ready and willing to tackle the movie's graphic sex scenes with costar Dakota Johnson.

"I'm a fairly worldly guy," the former Calvin Klein model, 31, says in EW's new issue, which features the first photo of him and Johnson on its cover. "I grew up in a very liberal place. I'm not saying we had a playroom, but I'm not shocked [by the sex in the book]. It's essential to tell the story. I can't believe films that don't invoke the sexual side of it. So it works for me."

His costar, 24, is also up for the challenge -- though she tells EW she's been working out more in anticipation of stripping down. "Obviously, I want to look good naked," she tells the mag. "I totally understand now why people exercise, because it kind of f--king feels awesome."

Also awesome? Getting cast in the film to begin with. Dornan scored the role of Christian Grey after Sons of Anarchy star Charlie Hunnam dropped out of the production, and he couldn't be more thrilled about stepping into the part -- albeit a bit late.

As he tells Entertainment Weekly, he got the news at 1:30 a.m. London time, while his pregnant wife, Amelia Warner, slept upstairs. "I was sort of pretending I wasn't waiting, but the phone was in my hand, halfway to my ear," he confesses.

A few minutes later, director Sam Taylor-Johnson called to tell him he'd gotten the role. "There was a slight fear," Dornan tells EW. "But beyond anything else, I was really f--king excited."