There's something I expected the author to say that never came: in order to have sex, first you must choose how to have sex. If a movie has a sex scene, it expresses an opinion about sex: how to have sex, why to have sex, when to have sex, and what kind of person would have sex like that. But opinions are dangerous: people might get mad at you if you have an opinion, but nobody can get mad at you if you don't.