Sex Perfect: The Art of Sexual Intercourse is the closest that Paula Russell came to illustrating a ‘straight’ sex manual. Published by the Erotic Print Society, it was the last time that she and ‘sex doctor’ David Delvin worked together on a project.

Paula’s pencil drawings, clearly done from life, perfectly complement Delvin’s clear no-nonsense text, making Sex Perfect a timeless sex education classic; it is a pity that the demise of the Erotic Print Society shortly afterwards has made the book almost impossible to obtain.

David Delvin (1939–2018) had a lifelong interest in clear thinking and writing about sex and relationships. After working with the Family Planning Association and the Institute of Psychosexual Medicine, he became a founding fellow of the Faculty of Family Planning of the Royal College of Obstetricians and Gynaecologists. He appeared on 930 TV programmes and wrote 34 books, including The Book of Love, which sold more than a million copies and became a family planning textbook. The book was a catalyst for videos such as The Lover’s Guide, and TV programmes including The Good Sex Guide, the flavour of which was summed up in a sequence in a snooker club – men were seen playing a ‘stick on the tail of the donkey’ game to find out if they knew where the clitoris was. Only half of them did.