Grayson Perry, the tranny potter, says no one has sexual fantasies about equality. Men and women don’t get off on wearing the same fleece and cruising down the aisle together in Waitrose sharing the same responsibility to find the mung beans, he says. I’ve heard him make this point a couple of times now: first was during his keynote at last February’s Being a Man festival at the Southbank Centre and most recently he said it again last Saturday, at the Southbank’s open think-in where people came to help them plan the next festival. Perry’s point is that sex always has a power dynamic going on. He implies that sex needs a power dynamic in order to work: you need one person doing the thing and one person having it done to them, whatever it is. They can switch roles of course, throughout their partnership or even in the space of a single night. Someone who has lots of power in society might want to wield this in the bedroom too, or he (yes, probably he) might want the opposite when the sexing hour starts. It’s why chief executives like to dress up as babies and be spanked, or whatever.