This particular image/narrative of Ancient Rome always seems to pop in any discussion about the decline and eventual fall of Rome. That is, Rome became a decadent, wanton society where everyone had sex in wild orgies and ate lavish banquets until they puked, and that is why Rome fell, or so the narrative goes.
I'm no expert on Rome, but the argument that Rome fell because of loose sexual morals and "debauchery/decadence/other similar scary word" seems really flimsy and moralistic to me. Where did this view of Rome come from? And is it actually taken seriously by any historians?
It could have partly come from the Romans themselves, or at least their literature. Tacitus, for example, spends much of his Histories expounding on the moral flaws and vices of many of the people he is discussing (portraying Vitellius as more interested in living a life of Imperial luxury than in prosecuting the civil war with Vespasian, for example), often exaggarating for political effect. If writing such as this and other propaganda were taken to be literally true, it would naturally contribute to an idea of Rome as decadent and debauched.
Edward Gibson's History of the Decline and Fall of the Roman Empire, which has plagued historians for now centuries but remains stubbornly latched to the public consciousness.
I don't think anyone in academia takes that view seriously today.