The Scarlet Letter (2004)

Policeman Ki-Hoon's life is duplicitous, oscillating between the amenable, newly pregnant wife and a very appealing mistress- the singer Ga-yee. His world gets shaken up when he gets news during a murder investigation that Ga-yee is pregnant and her obsession with him rules out abortion as an option. In a very twisted chance of fate, Ki-hoon and Ga-yee end up locked in the trunk of his car on the side of the road as raw despair brings to light the shocking truth about his wife and his mistress.