Erotic literature comprises fictional and factual stories and accounts of human sexual relationships which have the power to or are intended to arouse the reader sexually. Such erotica takes the form of novels, short stories, poetry, true-life memoirs, and sex manuals. A common feature of the genre are transgressive sexual fantasies on such themes as prostitution, orgies, homosexuality, sado-masochism, cross-dressing, incest and many other taboo subjects and fetishes, which may or may not be expressed in explicit language.