‘The loudest insect on the planet is a two-millimetre-long species of water boatman that uses its penis as a violin bow. Now that’s talent,’ Emerald mused. ‘Not to forget the swallowtail butterfly, which has eyes on its penis to help to position itself correctly during mating. And Indian stick insects, which stick together to have nonstop sex for seventy-nine days.’

Her zoological observations were drowned out by the opening chords of ‘It’s Raining Men’, which burst forth from the speakers. Twenty young male contestants immediately began busting out their moves, grinding and gyrating, wiggling and waggling, much to the tipsy delight of the mumsy throng.

Emerald immediately forgot all about stick insects, water boatmen and butterflies. ‘Woman overboard!’ she adjudicated as the song climaxed. ‘And it’s every woman for herself. I think I definitely need some mouth-to-mouth-resuscitation . . . although, full stomach-to-stomach-resuscitation would be even more life-saving.’

Entertainment officer Brent played the theme music from Jaws to allow time for the exuberant judges to put their hennaed and highlighted heads together in heated discussion.

Emerald was quick to give her own verdict. ‘Did you see the size of number seven? That guy could pole vault to Vanuatu on his own appendage. I definitely want to get to know him better . . .’

Amber jabbed Emerald in the thigh with a stiletto nail. ‘I’m sorry, but isn’t that a wedding ring I see on your finger? What about Alessandro? You’re always bragging about the prowess of your Italian stallion.’

Emerald’s face closed like a clam. ‘Sarcasm doesn’t suit you, Amber.’ Then she looked daggers at me. ‘I told you not to tell her!’

‘I didn’t. My lips are big but sealed,’ I protested.

‘Tell me what?’ Amber asked.

‘Come on, Emmy. I think we’ve drunk too much from the bottle to put any genies back in it,’ I pleaded, raising my glass in her direction.

Loosened up by two Slippery Nipples and an Orgasm, Emerald acquiesced. ‘Oh, Christ. Just don’t gloat, okay, Amber? I hate it when you exceed the daily recommended amount of smugness . . . My Italian stallion’s gelded.’

‘What?’ Amber canted a pencilled brow.

‘What’s said on the cruise stays on the cruise, understood?’ Emerald insisted in a piercing whisper. ‘I was relining a hamster cage with newspaper at work last week and glimpsed an article about marital sex. The headline read “Sex Ten Times a Year”, and I thought Gosh, that much?! I sneaked it back to my office to read it, and it went on to say that sex ten times a year means your love life is defunct. Hopeless. Dysfunctional.’

Amber shed her improvised beach-towel burqa and pivoted to face her older sister, leaning across my prone body. Emerald mimicked the manoeuvre, swivelling sideways. I lay between my warring siblings in a kind of human no-man’s-land.

‘Seriously? When was the last time you had sex?’ Amber probed, astounded.