Angel Eyes (1993)

Angel is a disturbed teen who becomes obsessed with her nice stepfather Steven. After her mother dies under unusual circumstances, Angel is sent to an institution. Years later, she is let out and tracks down her dear step-dad who now lives with his new girlfriend Michelle. He is technically her only kin so he takes her in, but his girlfriend doesn't like Angel one bit. Angel's obsession with her "dad" is as strong as ever and she fantasizes about seducing him. After spying on him and his girlfriend having passionate sex, she begins playing a deadly game and even tries to seduce his hostile girlfriend. However, Steven has a more immediate and obvious problem - a drug dealer called Johnny Ventura.