Alex Comfort, a British science professor specialised in the lifelong study of molluscs, thought he was writing ‘an antidote to war’. He, his wife Ruth, and her best friend Jane, an unconventional throuple in the quiet suburbs of 1970s North London, challenged societal norms, lasting a decade. It was the laboratory where recipes outlined in the manual, as well as the instantly recognisable hand-drawn sketches of hirsute hippies having sex, were born. The book was erotic, funny, and wholesome, reinventing sex and love for ordinary people and giving them permission to enjoy sex for the first time ever.