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. There is also some evidence that pornography can be used to treat voyeurism. Some productions are noted hentai movies for sophisticated and/or experimental storytelling and animation techniques. Freud, however, considered such extensions of sexual interest to fall within the range of the normal, unless marked out by exclusivity . Saliva pornography involves salivation and saliva. Greater economic and social freedom allowed them gradually to be able to determine how they could form relationships and families. Buck Angel is the best-known actor in hot gay sex this genre. Transsexual porn star Wendy Williams has stated that transsexual porn is classified as Straight Specialty. Insertion in pornography features women inserting various odd objects into their anus or vaginas. This is commonly called double anal or double stuffing. Erotic spanking is the act of spanking another person for the sexual arousal or gratification of either milf fuck or both parties. This technique may include the use of a simulacrum, or artificial vagina. The person sat upon may be in bondage, sexually submissive, or simply held down by the body-weight of the other person. Bobbi S. Reality Reality pornography refers to real or faked amateur encounters. The nipples are erogenous zones, and vigorous stimulation of them during masturbation usually causes the penis to become erect more quickly than it would otherwise. Cum-shot pornography features a collection of male ejaculation scenes. Anal sex or anal intercourse is generally the insertion and thrusting of the erect penis into a person anus, or anus and rectum, for sexual pleasure. Spanking or whipping pornography involves spanking or whipping, generally of the buttocks, with the hand or with other objects such as belts, switches, paddles, brushes, or whips. Matsuo used amateur actresses in his videos, and he usually traveled to their hometowns for the filming.