Up! (1976) - Russ Meyer

Adolf Schwartz, an exiled German with a penchant for perversion, has all the time in the world to indulge his intricate BDSM fantasies in his castle. However, his authoritarian lifestyle is taking a toll on his servants, who are no longer willing to take further humiliation lying down. When a bucket of piranhas unexpectedly ends up in Adolf's hot tub during a masochistic session, former servant Paul and his wife, Alice, team up with the busty hitchhiker, Margo Winchester, to uncover the culprit. Instead, passionate love triangles form, and the investigation veers off course when they find themselves caught up in a vicious cycle of corruption, jealousy, and murder. But first things first. Who killed Adolf Schwartz?