Jane Fonda, 'Book Club' co-stars talk surprising popularity of 'Fifty Shades of Grey' in 'puritan' America

In the upcoming comedy Book Club, Jane Fonda, Candice Bergen, Mary Steenburgen, and Diane Keaton play a group of friends whose introduction to the popular erotic novel Fifty Shades of Grey helps stimulate each of their love lives.

So naturally the legendary actresses did their homework and read the ubiquitous E L James book that has spawned two sequels and a blockbuster movie franchise. Fonda, in fact, will be the first to admit it didn’t take Book Club to see what the fuss was all about.

“I read it before I knew about the film, I was just curious to see what was stirring everybody up so much,” Fonda told Yahoo Entertainment this week at CinemaCon in Las Vegas, where she was joined by Bergen and Steenburgen (watch above). “I could see that it could stir women up.”

Unlike the women of Book Club, it did not change any of their lives: “I read some of it, I didn’t read all of it, frankly,” said Bergen. “Because it was such a big deal. It took the culture by the throat.”

Still, all three actresses expressed surprise that a book as sexually graphic as Fifty Shades would become as popular as it has in the U.S.

“I’m not sure people had read [this kind of] erotic material before,” said Steenburgen, noting that we haven’t seen a similar depiction of sex in popular literature since Anaïs Nin, whose diaries from the 1930s were popular in the 1960s.

“America doesn’t have it, the real erotica comes from France,” Fonda said. “So it was new for this country.”

Or as Bergen put it, “We’re a prudish country.”

“Puritan,” added Fonda.

Book Club opens May 18. Watch the trailer:

Read more on Yahoo Entertainment: