"Precisely because it must never take place, everything centers upon copulation. In films it is more strictly forbidden for an illegitimate relationship to be admitted without the parties being punished than for a millionaire's future son-in-law to be active in the labor movement."
Here Adorno and Horkheimer are making note of an example that demonstrates one of Foucault's points in the History of Sexuality: sexual "repression" as an explosion of discourse on sex. Sex is not allowed to be seen in general-audience films, so that is where all the juicy drama comes from. I'm thinking now also about daytime TV -- soap operas, anyone? Sex can't take place on these television shows, but all of these shows keep people coming back by constantly creating kerfuffles about who is fucking whom, who they used to fuck, why they shouldn't have fucked them, and the horrible consequences that will take place if anyone finds out that so-and-so fucked whats-her-name, and actually little Jimmy isn't really whats-his-face's kid.