Some techniques which may work for one individual can be difficult or uncomfortable for another. Gloryhole pornography features women performing fellatio on unidentified men through a small hole made in a bathroom divider. Related genres include: Amateur pornography originally referred only to pornography produced by amateurs but now also includes professionally made pornography designed to appear as if it were amateur. For uncircumcised males, stimulation of the penis in this way comes from the pumping of the foreskin, in which the foreskin is held and slid up and down lesbian hentai over the glans, which depending on foreskin length, is completely or partially covered and then uncovered in a rapid motion. Crying pornography that features participating gay sex video actors crying. Group sex is sexual momsex behavior involving more than two participants. Entacle erotica describes a type of pornography most commonly found in Japan which integrates traditional pornography with elements of bestiality and a fantasy, horror, or science-fiction theme. Although pornography has usually focused on heterosexuality, due to the prevalence of the heterosexual orientation, explicit gay material has a long history as well, which reaches back to Greek antiquity, if not to prehistory. The person sat upon may be in bondage, sexually submissive, or simply held down by the body-weight of the other person. Facial cum shots are currently regularly portrayed in pornographic films and videos, often as a way to close a scene. Actual upskirt or downblouse shots may violate privacy laws in some countries. Pegging is a sexual practice in which a woman performs anal sex on a man by penetrating the man anus with a strap-on dildo. Insertion in pornography features women inserting various odd objects into their anus or vaginas. Failure to honor a safeword is considered serious misconduct and could even change the sexual consent situation into a crime, depending on the relevant law, since the bottom has explicitly revoked his or her consent to any actions that follow the use of the safeword .