Dacryphilia
Dacryphilia (also known as dacrylagnia) is a form of paraphilia in which one is aroused by tears or sobbing.
The term covers all forms of pleasure from the tears of others. The arousal is achieved when viewing a person in emotional distress. It carries the theme where a person (often a Top in a BDSM relationship) induces another (the bottom) to cry, or otherwise show a strong emotion.
BDSM
Dacryphilia may be a form of humiliation in the 'pain/restriction/servitude/humiliation' spectrum of BDSM; for example, a dominant may verbally abuse the submissive in order to elicit a tearful response. In contrast, a Dominant may physically torture the submissive to draw tears in a pain scene. In this way, dacryphilia is a form of sadism.
The psychological aspects of dacryphilia are that the causative entity displays the power to control the psychological response from the receiver. This form of power-play therefore brings pleasure, and for some, sexual arousal. Passive dacryphilia involves a third party who also achieves pleasure in watching someone in emotional distress, usually caused by the scening dominant, though the reason does not restrict the pleasure - a person may enjoy the tears of others, whatever the cause.