What a strange question.
Is it sinful to inflict pain or humiliation on another for ones own amusement? Perhaps, although the context may mitigate the culpability.
Is it sinful to inflict pain or humiliation on another for discipline? That depends on whether or not the one doing the punishing is in fact in a position of authority, whether or not the person receiving the discipline actually deserves to be disciplined, whether or not the discipline is proportional to the infraction. May also depend on circumstance, presence of other persons, etc.
