The CDC reports that the number of heterosexual men and women who’ve tried it vacillates between 30 and 40 percent (oddly, the CDC doesn’t report on how many homosexual men have tried it, except in a statistic that weirdly combines it with oral). The book is amazing not just for its straight-up factual information on practically any aspect of sex you can think of, but also for its easy, nonjudgmental, at-times humorous tone. But the reality about anal is not, actually, that everyone’s doing it, says research psychoanalyst and author Paul Joannides, Psy.D., whose comprehensive book on sexuality, The Guide to Getting it On!, is used in college and medical school sex-ed courses across the US and Canada. First it was shocking, then it was having a cultural moment, now it’s practically standard in the modern bedroom repertoire-or so a quick scan of any media, from porn to HBO, will tell you.