This is a decent book that addresses a difficult subject, one that it is important to know about yet most people find hard to discuss. It is quite grand in its ambitions, and while a little useful I found that it didn't quite reach the heights.
Setting out to discuss all aspects of sex, from descriptions of the various bodily parts involved, methods of arousal, positions, health considerations etc etc, it is certainly ambitions. However, it did not go deep enough for me, with descriptions that just brush over the surface and told me nothing I did not know from school. The layout and general tone is also faulty - a book like this can either be a deep and informative text book, going into every subject chapter and verse; or a work of art such as the Karma Sutra; or a simple set of positions. Clever arrangements and too much humour do not really have a place. The authors have tried to structure the book as a menu for a meal, with starters, main course, dessert etc. This makes information hard to find, and by using euphemisms it almost feels a little like a Carry On film rather than the frank and open discussion that is required.
That said, there is useful information to be found here. I just think that a more rigorous and less euphemistic approach would have really lifted this to a height. 3 stars.