At the very beginning of Mad Max, one of the Big Bopper unit can be seen using his rifle to spy on a couple having sex in a field. As soon as they realise what's going on, they flee in the nude, likely terrified at both a) a cop watching them have sex and b) some stranger pointing a rifle at their vulnerable, naked bodies. Because what's a better way to kick off a movie than some gratuitous nudity, right? And yes, there is another Random Boning Couple later on...