Rule Number One

Steve and Mandy have always been inseparable, but their closeness breeds jealousy when Steve's girlfriend Millicent finds Mandy in his apartment holding a knife. Millicent issues an ultimatum: choose. Steve picks Millicent, straining his friendship with Mandy. Later, Steve dates Leah, a woman who seems perfect, while Mandy begins seeing Chris, a man Steve introduced her to. Mandy grows suspicious after discovering Leah rifling through Steve's personal documents and duplicating his keys. She warns Steve, but he accuses her of jealousy, driving a wedge between them. Mandy's fears prove justified when Leah is exposed as a spy for a rival company, stealing confidential client documents. Steve, devastated, apologizes to Mandy, and she forgives him. Their bond deepens into romance, but the transition is rocky from the start. They argue over trivial matters: Steve's possessiveness, Mandy's casual public behavior. Steve calls Mandy 'ratchet,' and she labels him a womanizer. The constant bickering exhausts them both, eroding the foundation of their friendship. In a restaurant, they acknowledge the truth: their romantic relationship has been a disaster. Mandy suggests breaking up, and Steve reluctantly agrees. They realize that mixing friendship with romance was a horrible mistake, leading only to unhappiness. Despite their love, they cannot make it work without destroying their long-standing bond. After the breakup, Steve and Mandy return to being friends, committing to never let romance interfere again. They learn the crucial lesson of 'Rule Number One': leave friendships alone. The film ends with them laughing together, their friendship salvaged and stronger for having survived the ordeal.