In BDSM, humiliation is one psychological technique a top may use on a bottom. It is generally considered edgeplay because it touches strong emotional buttons.
Humiliation is a highly subjective issue, and depends greatly on context. While in a dominant-submissive scene or relationship, the submissive takes a subordinate role and may be called "slave", "boy", "dog" or something similar. The submissive may also make displays of subservience, such as lighting cigarettes, walking a pace behind the dominant, only speaking when spoken to, etc.
However, a dominant generally does not call his or her submissive "fat", "ugly", "stupid" or "worthless" or otherwise insult the submissive; this would be considered abuse. Insults and other forms of humiliation should only be used when the top and bottom have negotiated the issue and are prepared to add this kind of play to their scene.
Depending on the roles and persons involved, terms like "slut", "tart", "bitch" and "whore" may or may not be considered humiliation. For some people, such names are a way of achieving ego reduction or getting over sexual inhibitions.
Sexual roleplaying may or may not involve humiliation. For example, one bottom who plays the part of a dog may enjoy being mock-forced into it and the top will emphasize the lowness of the bottom's status as an animal. Another dog-player would rather play the role of the dog without any element of humiliation.
One such form of sexual roleplaying is erotic objectification, where the bottom is cast in the role of an object.
