His big hairy foot is submerged and the tiny fish want to eat it.
Swarming like bees to honey, they dart and peck, searching for tasty morsels to munch on.
This is not an intentional plunge - it is dark and we've been drinking - but having ended up in the water, the toes stay put awhile to keep our feeble minds entertained.
And you can't blame us, really. How often do you holiday on a Pacific island and find yourself having to watch out for a moat full of foot-fetishist fish?
Hitherto, Rarotonga has not been renowned for its luxury accommodation. Bungalows-for-rent are commonplace among the roadside stalls and ragtag roosters.
The ill-fated Sheraton Hotel, which might have filled the gap, has been a white elephant since work stopped a quarter of a century ago.
Nowadays, security guards keep a sleepy watch over the graffittied eyesore that is the butt of many a local joke.
But, just a few kilometres down the road past the Papa Ben Store, where "Jesus is Lord" and George sells his beachside pizzas, you'll find the Rumours Luxury Villas, which offer unabashedly pretentious pleasure.
When you rise each morning from your four-poster super king-sized, veiled bed, the lagoon is footsteps away.
Kayak out to a coral break for a swim or, if togs seem a chore, a spa and private plunge pool await. Skinny-dipping is recommended. Even skinny backwards diving.
Waterfalls, inside and out, gush over man-sculpted rock faces at the flick of a switch.
The moat - home to tiny fish known as "kainamu" or "mosquito catchers" - winds its way around the courtyard and through the villa. It was just a matter of time before one of us stepped in it.
Fortunately, if you do something silly like that, no one needs to know.
As the website proclaims, the resort's owners pride themselves on anonymity and discretion in this A-lister hideaway that has private jets on offer.
Kiwi TV stars Charlotte Dawson and Paul Henry have raved about the place but eliciting a Hollywood name-drop proved as easy as extracting blood from a stone.
Needless to say, our boardies and jandals - and my make-up free face and wild mane - were the source of several double-takes when we told other tourists where we were staying.
Especially when they heard we were in the appropriately named Ultimate Villa.
This resort is unashamedly upmarket. And, with bubbly on arrival, multiple shower heads, a double-decker hammock and a bed the size of a helipad, it's also a place where romance is almost compulsory.
Commitment-phobic men probably shouldn't come.
Or they could follow my partner's lead and drop an "anti-proposal" disclaimer en route before the glamorous surroundings have a chance to take effect.
Romantic? No. Sensible? Yes, if you are 15 months into a long-distance relationship.
"Yes dear, I think we should probably try living in the same city first," I replied, to his relief.
But even without a proposal to celebrate, the villa is set up so that you don't have to (or want to) leave.
Top-notch restaurant food can be ordered in, the kitchen is fully equipped and cheffed barbecues can be booked at 24 hours' notice.
After a couple of hours spent throwing back Mount Gay and bubbly in the spa, we were ravenous when ours came knocking.
The feast of fresh fish, beef, chicken and prawns was seared to perfection, the paw-paw salad was to die for and the sticky date pud - a favourite for us sweet-tooths - capped it off. Then it was straight to our private movie theatre, to sprawl on the La-Z-Boys and let our fat bellies recover.
But the main pampering takes place 500m down the road at the Rumours' spa.
Here, a range of divine scrubs, massages and facials are on offer - but it was the Vichy Shower that I found intriguing.
This is essentially a padded platform with seven shower heads above, where water pressure, angle and heat are adjusted throughout.
It doesn't matter how many Brazilian waxes and invasive doctor visits you've had; ladies, there's something bizarre about a massaged shower with a woman.
"Okay if I rub here?" Maricel asks, before kneading my buttocks.
"Sure," I reply.
The next day, during our "couple's massage", Marrisa and Maricel work their magic as we lay in a blissful loose-limbed coma, topped off with a glass of bubbly.
"The couples come and fall more in love after this," Maricel says to me.
I think I love her.
Rachel Tiffen visited Rarotonga as guest of Air New Zealand Rumours Luxury Villas and Spa.