The way information is presented, the actually medium in which it communicates, influences how the message is understood.
Expressing sex can be done but it takes a certain skill. To write about it takes even more talent. How can it be made to sound real without sounding too corny, or on the opposite end of the spectrum, too graphic?
Roland Barthes was a French literary theorist, philosopher, critic, and rhetorician. He was quite crucial in developing many schools of theory: structuralism, Marxism, anthropology, semiotics, social theory, existentialism, and post-structuralism, just to name a few. No big.