The Insider.com

After gaining major fame and fortune with the Harry Potter franchise, author JK Rowling is back with a new book, but isn't too crazy about the erotic series, 50 Shades of Grey, that beat out Potter as the best-selling British book of all time.

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When asked if she had read the insanely popular S&M novel by E.L. James (what's with all the authors using their initials?), Rowling, 47, told The Guardian, "I promised my editor I wouldn't." She added that's she's "not wildly" interested in reading the books anyway.

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Rowling's new book The Casual Vacancy is said to address more adult content, including teenage motherhood, drug abuse, and prostitution. Could this new novel give 50 Shades a run for its money? Rowling sure hopes so. "The worst that can happen is that everyone says, 'That's shockingly bad.'"

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Which book series do you prefer: Harry Potter or 50 Shades of Grey?