I saw it like 10-15 years ago, or more.
I only remember a few scenes and part of the story.
So a guy brings home his girl (fiancee, maybe?).
And the women gets tangled up in an affair with her boyfriend's brother and with the father of the boys.
So in short it's an affair involving one woman and 3 men.
One distinct (sexual) scene that I remember: the woman wakes up in the middle of the night and goes to the kitchen (lights are off), where she's found by one of the boys who bends her over the kitchen table and has sex with her, meanwhile the father is outside and sees them through the kitchen's window, but they can't see him cause it's dark outside.