From Wikipedia -
Harley Quinn from the Batman media appears to suffer from a form of this, having fallen in love with The Joker while working at Arkham Asylum as a psychologist.
Hybristophilia "is a paraphilia of the predatory type in which sexual arousal, facilitation, and attainment of orgasm are responsive to and contingent upon being with a partner known to have committed an outrage, cheating, lying, known infidelities or crime, such as rape, murder, or armed robbery." The term is derived from the Greek word ὑβρίζειν hubrizein, meaning "to commit an outrage against someone" (ultimately derived from ὕβρις hubris "hubris"), and philo, meaning "having a strong affinity/preference for".[1] In popular culture, this phenomenon is also known as "Bonnie and Clyde Syndrome".