The Breakdown | The How
The Breakdown
This trope doesn't exist to generate suspense; it exists solely to annoy the audience and force unnecessary conflict between two women who should frankly be trading lawyer contacts.
The SFC is usually an ex-fiancée, childhood friend, or entitled heiress who believes the ML is a piece of property she misplaced in high school. Her entire personality is dedicated to proving the FL is unworthy. The ML, meanwhile, allows the SFC permanent, unlimited access to his life, his office, and his family gatherings, often excusing her behavior with, "Oh, she's always like that." This creates a scenario where the FL is forced to endure daily psychological warfare simply because the ML is a conflict-avoidant sponge.
The situation only escalates when the ML finally—finally—intervenes. But instead of delivering the clear, firm statement ("Leave her alone, I don't love you, and if you bother her again, I will file a restraining order"), he uses ambiguous language. He might say, "Please stop making her uncomfortable," or the classic, "You know my heart belongs to someone else." The SFC interprets this as: "Try harder, you’re almost there!" The ML, having completed his minimum required communication for the week, goes back to making eyes at the FL, leaving the actual problem completely unresolved.
The real payoff isn't resolution; it's the inevitable scene where the SFC directly assaults or sabotages the FL, forcing the ML to rush in dramatically. The only person suffering genuine consequences for the ML's spinelessness is the FL. The trope ultimately relies on pitting women against each other for the attention of a man who, frankly, deserves to be single until he learns the word "No."