Dolphins are considered such radiantly happy creatures that “dolphin assisted therapy” (aka, hanging out with dolphins) is practiced as a way to treat human physical and mental suffering. Well, maybe an open society is part of the dolphin’s allure, too. According to one study of 120 bottlenose dolphins in Australia, researchers found a lot of male dolphins enjoy “extensive bisexuality.” And not just that, but some pairs engage in “exclusive homosexuality,” reports Discovery News. Pairs, trios or small groups of male dolphins will form exclusive groups that are sexual, social, and sustainable. One herd of seven males spent 17 years together in an intimate and affectionate clique.