Definition:
Is a sexual behavior involving more than two participants. Group sex can occur amongst people of all sexes and genders. While this article discusses group sex among humans, but this behavior/type also occurs in other animal species such as bighorn sheep and bonbons.
In principle, the term of group sex is any sexual behavior/act performed by more than two partners can be referred to as group sex.
Status:
Group sex may take place in public place, at outdoor events, nightclubs, at massage parlors, brothels, sex parties, at purpose-built locations/ places such as sex clubs or gay bathhouses etc. In places where non-monogamous sex is not accepted or illegal, group sex is takes place in private or clandestine locations, including homes, hotel rooms, or private clubs.
