For someone I love to prefer another woman to me, to choose her body over mine even in the abstract, was once the most vile experience I could imagine. I could not bear to watch a film with Ciaran sometimes – wasn’t able to relax for the two hours in which he was seeing a person who was better to look at than me. I clawed my thighs slowly and deeply beneath the duvet. In my head I swore off sugar, milk, bread, anything that might nourish me. I vowed to wake at five a.m. and do sit-ups until I couldn’t breathe.