The EX [1996, USA, thriller, DVDRip]

Businessman David Kenyon never told his wife Molly that he was married before, for three years, to a highly unstable woman named Deidre. Molly discovers this fact when Deidre, who has just been released from a psychiatric hospital, pays an unannounced visit to the Kenyons. Deidre is the ex-wife-from-hell. As a teenager, she murdered her own sister, who was competing for David's affections. Deidre flirts enticingly with David, impersonates a child therapist to get close to David and Molly's son Michael, and takes an apartment across the street from the Kenyons. When David won't leave Molly, Deidre tries to ruin David by accusing David of hitting her. When Deidre kidnaps Michael from school, and holds Michael hostage in a remote cabin, David and Molly set out to rescue Michael.