"I was like, 'Get me on the next flight home to Brisbane from the Cook Islands,'" she remembers. "I said to the production team, 'I'm done – I've seen enough.'"
What pushed Davina over the edge was watching groom Ryan forcing himself to eat an oyster, then throwing it up.
But, due to her history of short-lived relationships, the 26-year-old bikini model chose to give him another chance.
"If that was to happen in real life, I'd just leave and I'd never text him back," Davina admits.
"For my own self-development, I did commit to this experiment, and I felt like it would be tapping out too early for me to give up after a week."
Davina was so committed to the relationship experiment, she slept with Ryan.
"It was only once," she adds. "We did try to get intimate. We did want something to happen."
But afterwards, she admits they still felt like brother and sister.
Davina says she and Ryan fought "all the time" and was disheartened that she wasn't falling in love, despite the beautiful setting.
"I cried every day," she recalls. "I'd look around and I'd just be like, 'I wish I was here with my mum.'"
For 29-year-old Ryan, he said his TV wife's emotions were all over the place.
"I called it the 'Davina-coaster', and that was a very rough ride," he says. "It was up and down, up and down, and she didn't know how she felt about me."
Despite being at a beautiful beachside resort, it didn't set the scene for romance.
"It wasn't the best of times for us," Ryan admits. "I didn't know how to ride the emotional coaster and I didn't know what to do from that point."