Casual sex is contact without a promise of a relationship. The frame can be a single night, a summer, or a standing Tuesday that both people refuse to call dating. Clarity is what keeps it from turning into an accidental heartbreak project.

Protection and testing still apply. So does the ordinary kindness of a glass of water and an honest goodbye. Treating a partner as disposable is not a requirement of the genre. It is just a style some people choose, and others should be warned about.

Feelings wander in anyway. When they do, the adult move is to say so, not to punish the other person for a contract they kept. If you cannot hear a no about exclusivity, casual was the wrong shelf.

Alcohol muddies the category. Sex that would not have been agreed sober is not casual. It is a consent problem.