She never felt that Scott made love to her. It was more of a naked mugging. No finesse, no tenderness, a hit-and-run romance. If he did talk at all, it was to feed her lines for some legal sexual fantasy that was playing out in his head: ‘Say “I yield to the authority of the bench,”’ he’d urge, or ‘Fondle my gavel.’ He clearly had no idea that a busy mum’s top bedroom fantasy involves discovering that her husband has picked up his underpants off the floor.

While Scott thrust away, Amber contemplated menus for two future events she was catering. Scott had no inkling of her distraction. The night she’d conceived their son she was mentally planning a Moroccan lamb recipe with fennel and garlic. Their daughter? Mango, crème and ginger meringue.

Scott definitely had his turbo-booster rocket thruster on tonight, with no moon landing in sight. The metronomic regularity of his lovemaking was inducing sleep. ‘Were you faking it last night?’ she imagined him asking her over breakfast. ‘No . . . I really was asleep,’ she’d reply.

Bored rigid and beyond exhaustion, Amber now used her emergency guaranteed ejaculation technique and tickled her husband’s prostate with a finger. It was disgusting but effective. In her mind she pictured herself just shoving stuffing up a bird’s bottom.

After scrubbing her hands in the bathroom, she returned to the bedroom to hear Scott snoring cacophonously. Great. Now she still wouldn’t be able to sleep. Exasperated, and at the end of her familial tether, she stomped back into the bathroom and rang my mobile.

‘I’m in, Ruby,’ she said as soon as I answered.

‘What?’

‘I’m coming on the cruise. I mean, how bad can it be?’ Amber rationalised. ‘If Emerald annoys me too much I’ll just make her walk the plank.’

‘Oh, Amber, that’s wonderful! What made you change your mind?’

‘Well, don’t tell Emerald, who will just gloat in a most nauseating fashion, but having sex with Scott puts me into a coma. And that whole doormat thing? It’s true. I am being walked all over.’

‘Don’t worry, you coma-sexual! You’re not alone. Perfect marriages are like orgasms – a lot of them are fake. Just look at Harry and me,’ I said, sadly. ‘I thought we were happy.’

‘And I also really want to be there for you, Rubes. I love you.’

‘I love you too. And. . . .’ Now was the time to tell the truth, I thought, as I lay all alone in my empty house, cradling the phone, looking up into the darkness. How could I continue to lie to my dear sister, especially after Amber had uncharacteristically revealed a vulnerability of her own? If not now, when? Just spit it out . . .

‘I’ll see you aboard HMAS Hedonism!’ I heard myself say.