Somewhere in the first year or two of living together, most couples quietly invent a language. Nobody sits down and drafts it. It assembles itself out of habit and repetition until a lamp left on at a certain angle, or the sound of a particular drawer opening, carries more meaning than a sentence ever could.

Somewhere around 1:40 in the morning, in a bedroom that looks entirely unremarkable from the street, a woman is performing a manoeuvre she has never once described out loud. Slowly, in increments, using the weight of one shin as an anchor, she is reclaiming eleven inches of duvet. Her husband is asleep. He will remember nothing. She will remember everything, and she will not bring it up at breakfast.