An expression defining the act of meeting someone so much younger, so much hotter and so much more willing than your current wife, that in the matter of hours you decide to leave a wife of 20+ years behind. The act must also be preceded by the existence of a perfectly happy marriage that showed no signs of weakness up until the moment you "go fiji"
We were all traveling for work and my coworker disappeared for a solid two days. He met some young hottie at the bar and immediately decided to divorce the old hag he had left at home. We knew the moment he met the girl that he was about to go Fiji.