What is the theme in The Satyricon of Petronius / The Apocolocyntosis of Seneca by Petronius?

The not so subtle main theme of The Satyricon is the sexual adventures of Encolpius, the narrator and main character, and his companions, Ascyltus, Giton and Eumolpus. The story begins with Encolpius and Ascyltus being led to a brothel where Ascyltus must fight off a client who has paid the madame for his services. The three young students are all given drinks with aphrodisiacs and become more amenable. Encolpius and Ascyltus are both in love with Giton, who at sixteen is a little younger than his friends. They are continuously in conflict over Giton, who is stolen back and forth between the two friends. When Encolpius is accused by a woman of violating her sacred religion, his punishment and that of Giton and Ascyltus, is to be continually raped by male prostitutes until she calls them off.