A married couple and a single man were marooned on an island that contained little vegetation save a single enormous palm tree. The men took run climbing the tree to scan the horizon for possible rescuers. After the months of isolation, the single man was horny as hell, and although the woman seemed willing to satisfy him, there was little chance for privacy. While manning her perch atop the tree one day, the single man came up with the idea.
"Hay, you two," he shouted down. "Stop that fucking!" The married man was bewildered, since he and his wife were sitting some distance apart.
The next day, the married man climbed the tree. After searching the sea for ships, he directed his gaze at the figures directly below him.
"Well, I'll be dammed," he muttered. "It really does look like they're fucking!"