==Legal Derivations== 

 The man need not necessarily be unaware of his wife's adultery.  Under the common law of England, and in many states of the United States until fairly recently, there was a conclusive presumption, "the strongest known to the law," that the child of a married woman is the child of her husband.  Thus, if a man was married to an adultress, it is possible that she would be able to pass off spurious issue and, in effect, require him to support children who are not his. 

 In England, it was once the law, and technically may still, be that if a person has sexual intercoure with the King's wife or with the wife of the heir to the throne, he is guilty of    treason and liable to be put to death, as he might pass spurious issue off on the King and the country.  Charles and Diana, fortunately for them, were permitted to get divorce.