Some fans of E.L. James and her "Fifty Shades of Grey" trilogy are unhappy about the rising popularity of another erotic series called "Crossfire" by Sylvia Day. But Crossfire has already bumped Fifty Shades at the New York Times trade-paperback-fiction best sellers' list Sunday. "Reflected in You," the second book in the Crossfire series is now at the top of the chart.

Still, E.L. James and her fans have no reason to be bitter. "Fifty Shades" has sold 40 million copies, and the trilogy had a strong 30-week run at the same chart.

Fans, however, couldn't help themselves. They point the observation that there are striking similarities between the central characters in the two series.

Fans Dump Christian Grey for Gideon Cross? 5 Things about Sylvia Day and 'Bared to You'

"Crossfire" chronicles the sex lives of young troubled billionaire Gideon Cross. His love interest is also a billionaire with a messed up head, socialite Eva Tramell. When it comes to sex, however, they are trouble-free.

The central characters in the "Fifty Shades" series are Christian Grey and Anastasia Steele. The man is a young controlling billionaire; the woman is a fresh college graduate, naïve about sex and the many twirly ways of living.

Sylvia Day answers Christian Grey-Gideon Cross similarities on Twitter:

During a chat session with book readers on Twitter, Crossfire series author Sylvia Day was asked to compare Christian Grey and Gideon Cross.

They're so different! "@caren_andaya: @SylDay What do you say about the comparisons between Christian Grey and Gideon Cross? #SylviaDayChat" - Sylvia Day ~ Author ‏@SylDay

Mr Cross is not exactly all about sadomasochism as Mr Grey was, in the beginning of the "Fifty Shades" series. But they both have a troubled past, and they're coping differently.

As for their initials, everyone is supposed to believe that CG and GC initials are just part of a coincidence. Also coincidental is the timing of release of Day's Crossfire series.

"It was the right book at the right time," Day told Wall Street Journal.

Day said she completed the first Crossfire book in December 2011. "Fifty Shades," meanwhile, went mainstream in March 2012.

Gideon Cross shout outs often mention Christian Grey

I need me my own Christian Grey or a Gideon Cross, either will do!! @RachelBelib

Ok although I love Christian Grey more I found my real live Gideon Cross today. I served this customer who reminded me of him. - Em ‏@emz_1989

OMG !!! Gideon Cross!!! #reflectedinyou - Julie Creusen ‏@Julsx11

Who needs mr Gray omg I want a Gideon cross!! Roll on 3rd part!! - dona ‏@chunkmooangel

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