The word has been somewhat expanded in the social sciences strong prohibitions relating to any area of human activity or custom that is sacred or forbidden based on moral judgment and religious beliefs.
"Breaking a taboo" is usually considered objectionable by society in general, not merely a subset of a culture. Sigmund Freud stated incest and patricide were the only two universal taboos and formed the basis of civilization.
Common sexual taboos in general society can include incest, necrophilia, miscegenation, adultery, fornication, pedophilia, homosexuality, intermarriage, bestiality, and masturbation.
Tales of sexual encounters of a more taboo nature including sexual stories of family and relations (incest) performing sex acts.