A topical favorite of religious people, particularly conservative Christians, is so-called 'sexual immorality'. What is that exactly? To the rational mind, that would mean sexual-related activity which (so long as all participants are willing, consenting adults) results in harm to another person, or creature.
A system creates shame and then creates a means of absolving the shamed of their shame, provided they adhere to the rules of those who run the system. Convenient.