This article does not have any sources. (March 2012)
Exhibitionism is a tendency some people have. These people derive pleasure from the fact that other people can see them naked, or while having sex. Exhibitionism is much more common in extraverts, especially people who have histrionic personality disorder.
Exhibitionism is more common in women than in men.
Enjoying watching other people have sex, or being naked, is called voyeurism.