In a trilogy of rather brilliant short films, WaterAid imagines how different society would be if it were men who lost the endometrium of their wombs every month. An accompanying survey of 2,000 people found that 78% thought the world of sport would change if men had periods; a quarter thought white sportswear would be banned and that men would brag about their periods; 21% thought that bookmakers would factor menstrual cycles into their odds.

The films bring this alternate reality to vivid life. Around the office photocopier, men compare flows: the heavier the better. In WaterAid’s second film, football commentators talk blithely about a player being the most likely to score because he’s “on day two of his cycle” and “right in the optimum performance zone this month”. Wait, there’s an optimum performance zone? I’ve come to the end of my menstruating life without realising that, and I haven’t realised that because there is nothing blithe or casual in how we talk about periods.

I’ve written for a few years now about the dreadful state of things in the developing world, where girls leave school because they don’t have a toilet or sanitary protection, and use sand or rags, or sell sex to buy pads. This is the serious point behind WaterAid’s satire: a petition to provide latrines or toilets for the 1.2 billion women who don’t have one. They have been timed, too, to appear just before Menstrual Hygiene Day, which is today. This satire isn’t new: Gloria Steinem’s wonderful essay If Men Could Menstruate still resonates, nearly 40 years after it appeared in Ms Magazine (“Young boys would talk about it as the envied beginning of manhood. Gifts, religious ceremonies, family dinners, and stag parties would mark the day”).