It's cruel to intentionally hurt somebody who loves you
Teresa's boyfriend unintentionally broke one of Teresa's prized possessions, her grandfather's watch.
Teresa wants her boyfriend to understand how much he hurt her.
Teresa tearfully explains to her boyfriend how much she loved her grandfather's watch.
Teresa destroys her boyfriend's cherished sound system and leaves a note telling him that he now knows how she feels about her broken watch.
Teresa's boyfriend is sincerely sorry and cares more for her because of her loss.
Teresa's boyfriend is heartbroken by her cruelty and loves her less.