A non-traditional girl-friend who a man dates as an act of rebellion, potentially resulting in the downward spiral of his mainstream, corporate life, (i.e. lusting after subculture chicks causes social status suicide).
My friend Pete is going through a mid-life crisis. He started dating a punked-out 'suicide girl' last month.
Joe was married and had a good job before he met his 'suicide girl' at the coffee shop.