Their relationship had ended but they were cuffed together at the wrist and still did everything together. The boy had lost the key and the girl made him suffer for it. He had grown fat; she still looked the same. He watched her change, still remembered the last time they ever kissed. His heart broke everyday. Hers did not. One day he grew so tired of being arrested to the girl he decided to saw off his hand. So he did. And the nub is a reminder that he had lost the key and she would never love him again.