Wow there, this is not about sex or anything kinky at all. Let me explain. At school I hated history as a subject. I didn't do badly at all, but it was the first subject I let go in favour of maths and science for my final years in high school. What does this have to do with this notorious sex manual? More than what you might imagine!
Unless you count the books about plotting, characterization, style, grammar, writing, etc., this book is the first truly non-fiction book I have read in years.
I am referring to James McConnachie's, The Book of Love. It describes the history of the Kama Sutra - its history and how it was originally intended to be used. I am by no means in a position to critique the contents - I am no expert in the field of history - but I have to confess that the book intrigued me. Enough. that I now own a first edition of James' book.