It would take a rather more brash soul than this reviewer to read Bonk on the train without blushing. There’s the unmistakeable title in bold pink lettering surrounded by drawings of humans and animals in acrobatic couplings. And as if that weren’t enough, there’s the laughter-inducing potential of Roach’s investigations into the often absurd meetings between science and sex.

Roach champions the pioneering scientists who persevered in studying a hitherto unmentionable topic, even when it meant the researchers and their spouses had to volunteer as test subjects, or that they were labelled perverts. Of Marie Carmichael Stopes, a pioneer of family planning in Britain, she writes, “You have to marvel at a woman who, in the 1920s, in the name of science, was masturbating with a speculum in place and a mirror between her legs.”

Alongside the bizarre situations, much of the humour in Bonk comes from the obfuscations of scientific language. “There are vaginal floors, vestibules, platforms, barrels, and outlets,” she notes, wondering whether people are having sex or looking at a floor plan from a store like Ikea.

To her credit, Roach is suitably restrained when it comes to her use of double entendres and manages to avoid both coyness and gross-out humour.

She’s also a fan of footnotes, which are dispensed liberally, sometimes taking up as much as half of a page. Some of the most delightful pieces of trivia are tucked away in these addendums (“One of the less prominently known similarities between pigs and men: they both fondle breasts. No other males on the planet regularly do this.”) The tendency to diverge at a tangent to the topic at hand seems to work given the conversational tone of the book, but could prove annoying to readers who prefer a more direct approach.

If you’re after an in-depth social history or a guide to mind-blowing sex, this is not the book for you. If you’re after a rollicking good read, this is it.