Which behavior is primarily associated with voyeuristic disorder?

The association of voyeuristic disorder with the act of watching individuals engage in sexual activity stems from the central characteristics of the disorder itself. Voyeuristic disorder is defined as deriving sexual arousal from observing unsuspecting individuals who are naked, engaging in sexual activities, or undressing. This behavior typically does not involve any direct participation in the sexual act; rather, it is focused on the act of watching others without their knowledge or consent.

In this context, the other options reflect behaviors that are not characteristic of voyeuristic disorder. Actively participating in sexual activities indicates engagement rather than observation, which contradicts the core principle of voyeurism. Obtaining pleasure from another's suffering aligns more closely with sadistic tendencies, which is a different psychological condition altogether. Seeking consent before engaging is contrary to voyeuristic disorder, as the essence of voyeurism involves a lack of consent from the observed individuals, emphasizing the clandestine and non-participatory nature of the behavior. Thus, option A accurately encapsulates the essence of voyeuristic disorder.