Making a pearl necklace is one of the activities that sex workers use as safe sex alternatives for people who refuse to wear condoms. Voyeur or peeping Tom pornography is usually more staged with the subjects aware of the cameras, sometimes openly including this exhibitionist awareness. Group sex can occur between people of all sexual orientations and genders. Though the term anal sex most commonly means penile-anal penetration, sources sometimes use the term anal intercourse to refer exclusively to penile-anal penetration, and anal sex to refer to any form of anal sexual activity, especially between pairings as opposed to anal masturbation. 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. The first film was released in 1980 starring Kay Parker. Interracial pornographic films have experienced an explosion in popularity, becoming one of the fastest-growing and biggest-selling genres. The interaction between tops and bottoms—where physical or mental control of the bottom is surrendered to the top—is sometimes known as power exchange, whether in the context of an encounter or a relationship. 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 hentai porn secretary, often fake. Saliva pornography videos porno gay involves salivation and saliva. The first pegging scene appears to have been in the non-pornographic 1970 film Myra Breckinridge, based on the novel of the same name by Gore Vidal, although it was not explicit. High heel pornography involves women or men dressed in high heeled shoes. Arousal may be triggered by seeing the body movements or facial expressions of that person. Hentai is the various forms of Japanese pornography, including H-manga, H-anime, and H-computer games. Bareback naked milf sex is physical sexual activity, especially sexual penetration, without the use of a condom.