In six of the twelve Homeric passages in which Erinys or the Erinyes are mentioned, the common denominator is a crime or insult that occurs between blood kin: The Erinyes take action when a son steals his father's concubine, a son kills his father and marries his mother, two brothers argue, a son angers his mother, a man kills his mother's brother, or a son chases his mother out of her home.
Source: wiktionary