Breaking someone's heart-or wounding it, if you're in a more casual relationship-really effing sucks. We always focus on how to heal a broken heart after being dumped, but we never acknowledge how crappy it is to be the heartbreaker. This is why I chose to do my master's research in the area. Ending a relationship-whether it be a casual one or a marriage-is thick with anxiety, guilt, and conflict. And thus, what do we tend to do?