Some pornographic films use an artificial semen substitute to simulate or enhance creampie shots. Reality pornography is a genre of pornography where staged scenes, usually shot in cinéma vérité fashion, set up and precede sexual encounters. Its gain in prominence has been attributed to its depiction in the film Pecker, which was released in 1998. Group sex pornography features at least two men and two women , usually more, who all perform sex acts on each other. Breast fetishism is a paraphilic sexual interest focused on female breasts . Such works have also often been subject to censorship and other legal restraints to publication, display or possession. Barebacking usually refers to a conscious and deliberate choice to forgo condoms. A celebrity can fight the release in court to maintain deniability while still enjoying the career benefits. The queening stool is also related to a smotherbox, which also allows the person under the seat to be locked in place, restrained by the neck as in a set of stocks. Andrews cross or spreader bars. Concerted deployed sexual rejection exercised on the partner can be an aspect of Dominance and Submission as well. Threesome or 3some pornography features one man and two lesbian milfs women . The term has also applied lesbian hentai to other professions and even companies trying to appeal to a gay demographic. Perhaps following the example set by gay pornography, they have become a popular subgenre within heterosexual pornography since the turn of the century, featuring both vaginal and anal ejaculations. Medical pornography involves sexualized medical, often fake, gay twinks including gynecological pelvic examinations, rectal examinations, and pelvic or gynecological ultrasounds. Some prefer a particular type of clothing to urinate. The niche popularity grew significantly in the latter half of the first decade of the 2000s. The industry generally refers to such films as adult films, which is part of adult entertainment. Bukkake pornography involves a performer, usually female, onto whom several men or women ejaculate, usually on the face.