Concerns Rise Over Bondage Depiction in 'Fifty Shades' Robert Dunlap, a certified sex educator from California, gets three or four requests a day from couples expressing an interest in and even seeking coaching for the latest trend in kink -- BDSM, an overlapping acronym for bondage and discipline; dominance and submission; sadism and masochism. "It's such an explosion," said Dunlap, co-founder of the online site, Sex Coach University. It's happening now because of the book. The book, E.L. James' trilogy "Fifty Shades of Grey," has sold 32 million copies since its e-publication earlier this year and spawned the new cultural phenomenon. "It's absolutely been astounding how many students we get inquiries from on a daily basis," he said. Dunlap is also getting requests from sex educators to learn proper coaching in the practice. Devotees say that even though the popularity of the book "normalizes" what used to be a fringe sexual practice, they worry that a piece of fiction gives BDSM a "bad" name. "On the one hand if you are looking at it as a formulaic romance novel, it fits the formula perfectly," said Emily Prior a BDSM/Kink/Fetish teacher at Sex Coach University and director of the Los-Angeles-based Center for Positive Sexuality. But if your audience is people who already are in a lifestyle or are being introduced to the lifestyle, it starts to give misinformation. "It perpetuates the ongoing idea that people who do this are broken in some way," she said. And this is not true. Dunlap, who has chronicled the practice of BDSM, interviewing hundreds of fetishists for his 2001 film, "Beyond Vanilla," said that the practice demands strict rules of safety. "When two people want to get involved, their negotiation is up front," he said. They are going to have a safe word: 'When I say, it ends. Period. Most use a stop sign. Green means 'go.' Yellow means 'caution' and 'red' ends it. "Play is also negotiated," said Dunlap. For example, if you are doing flogging or whipping, 'Tell me during the process if you want to be hurt. Is it too hard? Is it too soft?' The BDSM craze has hit Britain, as well, according to Susan Quilliam, a relationship psychologist and sex advice columnist who is writing an academic piece on the trilogy for the Journal of Family Planning as well as running an exploratory workshop for the British couples. "'Fifty Shades' has been roundly criticized by the BDSM community and its depiction of the lifestyle is inaccurate," she wrote in an email to ABCNews.com. Christian Grey's initial seduction of Anastasia breaks every rule in the BDSM book. Quilliam said the relationship portrayed in the book is exploitive "on both sides and therefore emotionally unsafe and not sane." The book views Christian Grey as dominant because of an abusive childhood, which practitioners claim is an "untrue reflection." Most importantly, Quilliam worries about couples who experiment with BDSM for the first time based on the book. Bondage and Sadomasochism Not 'Mainstream' But sex coach Prior said the books are not "suddenly going to make this all mainstream -- that's silly ... What's fantastic about it is that it shows [BDSM] is not abnormal and people can allow themselves express themselves within their relationships. She said BDSM encompasses a wide range of sexual acts "from zero to 60." "It's not all extremely pain related, harsh and serious sadistic-masochistic behavior," Prior said. There's a whole lot of other stuff, too and it has every range to it. And Dunlap argues that "Fifty Shades of Grey" has one "powerful" message to readers that can protect couples from violence. "People should sign agreements that this is how they are going to play," he said. That's how the majority in BDSM do it â¦ There is a contract so everything sexual is agreed on up front. In clubs where BDSM is practiced, members who overstep the rules are ostracized, he said. "I was shocked at the popularity," said Dunlap. People have become much more sophisticated about what they want to do. When I was a little boy my uncle said something to my aunt: 'You are going to get a spanking later.' Then, I thought, 'Oh my god, what did she do?' Now that I am older â¦