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The Phaedra complex (/ˈfiːdrə, ˈfɛdrə/) is an informal, non-scientific designation to the sexual desire of a stepmother for her stepson, though the term has been extended to cover difficult relationships between stepparents and stepchildren in general.
When Hippolytus refused Phaedra's advances, she falsely accused him of propositioning her. Phaedra eventually killed herself in remorse after his subsequent death.
Cultural analogues
Amata in the Aeneid has been seen as cognate to Phaedra in her love for her future son-in-law Turnus and her eventual suicide at the news of his death.
In the Hebrew Bible, Potiphar's wife Zuleikha made a pass at Joseph, but Joseph refused her. So, Zuleikha accused Joseph of rape and he was put in prison, but eventually released. According to the tradition, Zuleikha made advances at many of her foster children before Joseph.
In the ballad Child Owlet, Lady Erskine propositions her nephew, and upon rebuttal accuses him of attempting to seduce her, leading to his murder.
Other use
French philosopher Georges Bataille used the same term in a very different sense to describe the morbid desire for a corpse.