And don't expect the actor –- who had explicit gay sex scenes in "Queer as Folk" –- to balk at the racy material: "If I could do it when I was 18 with a guy, I can certainly do it at 33 with a lady."

Charlie Hunnam is ready to go from biker bad boy to billionaire sex symbol.

During the season-six premiere of his FX hit, Sons of Anarchy, Hunnam opened up about his Fifty Shades of Grey co-star Dakota Johnson and how he landed the role of Christian Grey.

"As soon as we got in the room and started reading with Dakota, I knew that I definitely wanted to do it, because there was a tangible chemistry between us," Hunnam told The Hollywood Reporter and a handful of reporters. "It felt kind of exciting and fun and weird and compelling, and so that was it."

Before that electrifying reading, Hunnam spoke at length with director Sam Taylor-Johnson about her thoughts on the role. After their first meeting, he "felt really intrigued and excited about it."

"I went and read the first book to get a clearer idea of who this character was and felt even more excited about the prospect of bringing him to life."

But at first he was cautious about taking on the commitment, given that he's been locked into a TV show since 2008. After more talks with Taylor-Johnson, the filmmakers pushing back the shooting schedule to give Hunnam more time to prepare, and the reading with his future co-star, the actor committed.

Does he have worries about portraying such racy material onscreen?

"My first job was on a Channel 4 miniseries called Queer as Folk. [There were] incredibly explicit sexual scenes with a man," Hunnam said. "I mean, I'm 16- and 17-years wiser now. So if I could do it when I was 18 with a guy, I can certainly do it at 33 with a lady."

He also said his girlfriend, jewelry designer Morgana McNelis, helped him make the decision to take on the role.

"It's very hard to be with an actor, Hunamm said. "She's required to share parts of me that she wouldn't really want to share. With the nature of this role, that's going to be times 10."

He added that McNelis "loved the books."

"She read them and loved them and was really excited about the potential of the opportunity for me. If anything, I think it will make us closer. "

Fifty Shades of Grey, adapted from the EL James novel, will be released by Focus Features on Aug. 1, 2014, in North America.