Exhibitionism is a gay fetish where a male likes to show off his exposed sexual body part. Generally, to be considered an exhibitionist, you show off your exposed sexual body part in a situation where it would generally not lead to sex. For example, showing off your sexual body parts in your bedroom to your partner would generally not be considered exhibitionism.
Most exhibitionist expose themselves either in public places or when they are among a group gathering environment. Also, if you enjoy being watched by others while having sex, you are considered an exhibitionist. Have you ever mooned or been involved in mooning? Well mooning is considered exhibitionism and you may have been a exhibitionist at one point in your life without you knowing it through your innocent pranks.
