Bestiality pornography involves the sexual attraction of humans to animals. Partners can engage in penetrative sex, known as full swap, or choose to soft swap in which they engage only in non-penetrative sex. The sub-genres usually conform to certain conventions, and each may appeal to a particular audience. Jail/Prison/Police pornography involves people in police custody or inmates in jails or prisons in various sexual situations, such as strip searches or body cavity searches. The term bareback is used less frequently in the porn milf heterosexual community. Bodily functions Menstrual or red rhapsody pornography features gay twinks sexual activities involving women who are menstruating, with a focus on the menstrual blood. Com, there are only 3d hentai 655 bisexual titles out of a catalogue of more than 90,000 films. Actors are mostly amateur; any well-known actors in bisexual porn tend to be from the gay pornography industry. Teacher and Student or Boss and Secretary pornography involves sexualized situations which take place between an authority figure, such as a teacher or boss, and an underling, such as a student or secretary, often fake. Caro rejected that as being a necessary conclusion, stating that female fatty deposits on the hips improve individual fitness of the female, regardless of sexual selection. Some productions are noted for sophisticated and/or experimental storytelling and animation techniques. Masturbation involves touching, pressing, rubbing or massaging a person genital area, either with the fingers or against an object such as a pillow; inserting fingers or an object into the anus ; and stimulating the penis or vulva with an electric vibrator, which may also be inserted into the vagina or anus. Transwomen are most often featured with male partners, but are also featured with other transsexuals or cissexual women. Solo pornography features performers masturbating. Squirt pornography involves women ejaculating. However, sex researchers and adolescent health care professionals have found no evidence for the existence of rainbow parties, and as such attribute the spread of the stories to a moral panic.