Four Simple Rules

Ron, an inveterate philanderer, runs the restaurant Deux Amis with his friend Pete. Ron's wealthy mother-in-law pays the bills and keeps the place afloat; she also suspects that Sam's cheating on her daughter and promises to stop supporting him if he proves unfaithful. Sam is confident he can elude detection, because he has adopted four simple rules that he promises Pete he'll follow at all times. Are they fool-proof, and can he stick to them?