Last November, Emma Thompson—the actress with whom we’d most like to share a bottle of white wine—revealed that she taught her 13-year-old daughter, Gaia, about sex by creating “a handbook on sex and emotion.” She explained, “I drew pictures and said, ‘You know, you can sometimes feel things in your loins you don’t feel in your heart, and you need to look at that.’” As it turns out, however, Thompson was not the first member of her family to teach a daughter about the birds and bees by non-traditional means.

In a new essay for The Sunday Times, Thompson’s mother, Phyllida Law, who is also an actress, explains that at a very young age, Emma Thompson learned about sex after asking Law’s co-star, Sir Alec Guinness, about it. And rather than shy away from the subject, The Bridge on the River Kwai star gave the small child an adult explanation. Law recalls, “Emma, aged eight, once asked Alec Guinness about the details and he gave her a calm and accurate response: very helpful, though I felt a bit faint.” Law writes that Emma’s smaller sister, Sophie, who was on hand for the exchange, was transfixed by the Oscar winner’s Sex 101 lecture: “Sophie, then five, listened gravely, fixing him with her headlamp eyes.”

Law did not leave all of the sex-ed lessons to Guinness, though. She seems to take credit for being the first member of her family to create a sex manual. “I think I drew pictures,” she recalls of the visuals she provided her daughters. “My husband was blunt and I did the diagrams. I think we laughed. Sex is ridiculous behaviour from adults who tell you not to pick your nose.”

Perhaps everything you ever wanted to know about the sex education of Emma Thompson’s family?