Nothing unhealthy in promiscuity and orgies? The people's moral standards have indeed fallen low. This sort of behavior spreads diseases like a wildfire. As for why people seek this, it's because it's easy to project your demonic fantasies onto a person you don't know. Once you get to know your partner well, his or her personality dispells your imagination and you have to behave in a more upright manner. It's probably why it's common to wear masks on such events.