In the threesome scene in Wild Things (1998), Sam Lombardo says these words:
Never let the sun go down on an argument.
What does he mean by this expression?
He's basically telling them to kiss and make up after their fight, which of course takes on another meaning in this context. It's an old saying, usually applying to couples, that recommends they settle their arguments before going to bed rather than letting the animosity fester overnight.
It actually originated from the bible:
Do not let the sun go down while you are still angry, and do not give the devil a foothold. [Ephesians 4:26-27]