Incest
Related: incest in fiction - criminal offence - family - taboo - sexuality
Definition
Incest is sexual activity between close family members. It is a taboo in most societies and a criminal offence and an impediment to marriage in most countries, as well as being against most modern religions. But the exact definition of what is a "close family member" varies widely: some jurisdictions consider only those related by birth, others also those related by adoption or marriage; some prohibit relations only with immediate family members and ancestors or descendants, while others prohibit relations with aunts and uncles, nephews and nieces, and cousins as well.
The term is also sometimes used metaphorically, to describe relationships between an authority figure and a pupil, such as teacher-student or troop leader and scout, or between those who are closely related in some other nonsexual way, as in an "incestuous relationship" between stockbrokers and mutual fund managers. --http://en.wikipedia.org/wiki/Incest
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