There was a movie i watched a while ago.
I'm sorry if i'm breaking your brains but i can't remember much of it.
The woman is in love with a man, but she has sex with another man. Finally she kills him with some kind of steel stick, the man was tired of the sex, and the woman killed him with that stick while he was asleep (the whole scene is in a car) When she killed him she see's the man she loved and smiles to him, they fall in love.
That's all i can remember.
Thanks already :)
Is it Basic Instinct 2?
Spanish director Pedro Almodovar made a movie like that back in the '80s. It was called "Matador". May be that's the one.