Pornography can be classified according to the physical characteristics of the participants, fetish, sexual orientation, etc., as well as the types of sexual activity featured. 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. They cited the Internet and text messaging as common ways of organising meetings. This is commonly called double anal or double stuffing. Fantasies of group sex are extremely common among both men and women, and group sex hentai porn is a subgenre in pornographic films. One or more of the participants may engage in autoerotic sexual lesbian milfs activity, such as masturbation, possibly without physical contact with the other participants. Felching involves drinking recently ejaculated semen from the vagina or anus. There is also some evidence that pornography can be used to treat voyeurism. Squirt pornography involves women ejaculating. One-sided male gay twinks nudity can also arise when a male disrobes as part of a male striptease. The effect is to give the viewer the sense that they are experiencing the sex acts that they are watching, as opposed to simply watching others as a voyeur. Group sex can occur between people of all sexual orientations and genders. Practitioners have described going to public places such as a mall or a park. Solo pornography features performers masturbating. 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. Pornographic films or sex films are films that present sexually explicit subject matter for the purpose of sexual arousal and erotic satisfaction of the viewer. Scenes of multiple penetration are common in pornography. Bukkake videos are a relatively prevalent niche in contemporary pornographic films. The anal and rectal tissues are delicate and do not provide natural lubrication, so they can easily tear and permit disease transmission, especially if lubricant is not used.
