Phaedra, daughter the King Minos of Crete, is Theseus' second wife, who he marries after ditching the Amazonian Queen, Hippolyta. Phaedra is also the sister of Ariadne who Theseus ditched on an island after she helped him in quest to kill the Minotaur. So yeah, Theseus has a thing for stringing women along and then ditching them. (Some hero.) In Phaedra's case, however, Theseus gets a taste of his own medicine when she falls in love with Hippolytus, Theseus's son by Hippolyta.
When Hippolytus rejects Phaedra's advances, she gets revenge by telling Theseus that Hippolytus raped her. Theseus then asks his father Poseidon to curse Hippolytus, and the beautiful boy is dragged to his death by his own horses after a bull charges at him from the sea. And so Phaedra goes down in a long list vengeful females in Greek mythology. Of course, unlike oh say Medea, Phaedra feels horrible for what she does and commits suicide.
All the badness between Phaedra and Hippolytus has been irresistible to many playwrights for many many years. Famous tragedian Euripides puts his spin on the story in his tragedy, Hippolytus. The tale is also told by French playwright Racine in his Phaedre and by modern British playwright Sarah Kane in her gruesome play, Phaedra's Love. The story is also the basis for Eugene O'Neill's Desire Under the Elms.