In pornography, depictions of lesbian sex form a popular subgenre, directed toward a male heterosexual and female homosexual audience. Said that the female buttocks evolved in the context of females competing for the attention and parental commitment of powerful resource-controlling males as an honest display of fat reserves that could not be confused with another young gay porn type of tissue, although T. Yiff or Yiffy pornography features Furry or anthropomorphic animals in an erotic or sexual context. With second wave feminism and growth of scholarship in women history and sexuality in the 20th century, the definition of lesbian broadened, sparking a debate about sexual desire as the major component to define what a lesbian is. Partners can engage in penetrative sex, known as full swap, or choose to soft swap in which they engage only in non-penetrative sex. An orgy is a gathering where guests freely engage in open and unrestrained sexual activity or group sex; and a bunga bunga orgy is an orgy in which participants have sex underwater, such as in a swimming pool or a hot tub. This category also includes pornographic home movies. This is also the case in many relationships not considering themselves as sadomasochistic; it is considered to be a part of BDSM if it is practiced purposefully. Discipline big tit milf often incorporates sadomasochistic aspects, 3d hentai though some sadomasochists distance themselves from D/s practices such as punishment. But starting with The World Biggest Gangbang , starring Annabel Chong, the pornographic industry began producing a series of films ostensibly setting gangbang records for most consecutive sex acts by one person in a short period. Such films continued to be produced but could only be distributed by underground channels. Buck Angel is the best-known actor in this genre. Since at least 1973, it has also been used to refer to a sexually attractive young woman. Sub-genres of Japanese porn Among the various sub-genres of Japanese pornography are the following: Lolicon ロリコン: This genre involves prepubescent and adolescent girls between the aged of 6-12.