Mitchell calls the idea of later-life sex on screen “a taboo because it’s so rare” and Andrew Haigh has his own theory about why audiences can react with shock, and even disgust. “The warped view we have comes from when we are very young, I think, and our first relationships with older people are usually our grandparents. They just, for the most part, don’t ever talk about sex, so I think we just don’t understand the need or desire even existing.”

Even deeper than this, suggests Dr Rebecca Jones, a lecturer specialising in older sexuality at the Open University in the UK, is that humans have what she calls “a psychological glitch – which is almost always down to us thinking about our parents or grandparents having sex. We make the mental association and we can recoil from it.

“You’d think we’d be smarter about it as nearly all of us are going to be old one day, but of course we also subscribe to a youthful standard of beauty, and hold up the gold standard of sex as between people in their twenties,” she says.

Ancient prejudice

The idea that to desire sex past into middle age and beyond is somehow repellent has endured since antiquity; Aristophanes was writing about ‘the cougar’ long before Courtney Cox; in his comedy The Assemblywomenfrom 391BC, women take over the Athenian parliament and pass a decree that if a man wants to go to bed with a younger woman, he is forced to make love to an older one first.