She was wearing a wetsuit and he asked her if she had just been for a swim.
Soon after stating the absolute obvious and feeling a little foolish, he departed for the Abu Dhabi Adventure Challenge, but fate ensured they kept bumping into each other when he returned to town.
Once they became an item, Ms Nunn was inducted into the Dougal Allan support crew and accompanied him to the 2010 Coast to Coast World Multisport Championship, where he finished as second individual.
She prefers to act as an "emotional" prop in these tough races and let others concentrate on co-ordinating equipment, nutrition and hydration.
"I'm really lucky that we do have the same interests, so going to an event, even if I'm not participating, I love the atmosphere and supporting him."
Originally from Melbourne, Ms Nunn (28) moved to Wanaka three and a-half years ago and recently spent three months in Europe. Before and after her trip, Dougal was racing in China, lengthening their time apart.
"We've been together almost the same time we have been apart," Amy said.
Even when they are both in Wanaka, Dougal fits 25 hours training a week around four working days, while Amy works in a bike shop and is preparing for her second Challenge Wanaka half-distance triathlon.
She shares a love of fitness with her man and mountain bikes, runs, swims, road cycles and works out at the gym.
"Finding time sometimes to spend together is a bit of a mission, but neither of us would change anything," Amy said.
They don't train together, except for a running group organised by Dougal's coach, Val Burke, or the occasional body balance class, but Amy will ask him for feedback on her exercise programme.
"All the stuff that I do, I'm not competitive with. I enjoy the social side and health benefits, rather than wanting to win races," Amy said.
That doesn't mean she doesn't appreciate and admire Dougal's drive to establish himself as a consistent performer on the international adventure-racing stage.
"He is really driven and focused on wanting to better himself and continue in sport. He's really passionate about it."
