Amber’s face became a little, balled-up fist. She jumped on Scott’s back and thumped him. ‘Stop it, Scott. It’s not his fault! It’s all your fault. If only you’d ever encouraged or praised me! Harry didn’t take me for granted. He loved my food. Unlike you. He thanked me profusely after every bite!’ Amber seemed to have mistaken her husband for a piñata. She was banging and whacking and thwacking his back as though he were full of treats. Her gleeful animation seemed to be bordering on the thin edge of hysteria. ‘You always told me how gentle Harry was in bed – I wanted that. For a man who spends every waking moment so engrossed in human rights cases, my husband has a hard time being human. Whereas Harry actually talked to me – not monologued, but really talked. He would sit at the kitchen table and chat for hours.’

‘I think you did a bit more than chat, Amber.’ I was trying to make my teeth grind more slowly so as to muffle the sound of disintegrating enamel.

‘You have no idea how lonely it is being married to him. I sometimes think about getting myself taken hostage, just so Scott will take notice of me outside the bedroom. And what about my human rights?’ She pummelled her husband’s back again. ‘You can catch despots who launder millions of dollars but don’t know how to wash your own underwear. Really?’ Then Amber, who hated hugging, slid off her husband’s back and splayed her arms to me. ‘But what I did was wrong. Deeply, profoundly wrong. Please, please forgive me. I was not in my right mind.’

I winced away from her, feeling a queasy mixture of horror and also some grim satisfaction that at least my accusations about Harry’s infidelity had been proven, despite his gaslighting. But with my own sister? It was like being dropped straight into a Greek myth.

‘Do you think she’s on something?’ Emerald asked me.

‘Yes. My husband’s face, unfortunately,’ I replied, gutted.

‘The emotional libido, that’s what’s important to women,’ Amber addressed her husband’s vinegary expression. ‘Not just sex, sex, every bloody day, over and over and over. Wham, bam, no thank you, ma’am.’

‘Sex every day, over and over and over . . . Jesus, have you any idea how lucky you are?’ Emerald said wistfully, glaring with resentment at her well-built but impotent spouse.

‘Why didn’t you two just swap husbands? That would have solved everything!’ I tried to shout, but my voice was juddering and broken. ‘Have some husband replacement therapy.’