Bag with a severed head, slippery fight on bloody floor, cheating husband

I remember a few scenes, which I believe were from the same film, but memory is fuzzy: - A man is cheating on his partner with his secretary. He bangs her on the couch in an office (construction site trailer?), causing her hand to scratching the wall. The scratches on the wall have made it bare, indicating this has gone on for a long time. - The final scenes involve a slippery fight on a wooden floor covered in blood. - I believe there’s a bag with a severed head in it. - Probably from the 90s.