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. 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 . POV pornography involves camera angles designed to provide the viewer a view similar to that seen by one of the participants, whose face is never shown. Strictly speaking, bondage means binding the partner by tying their appendages together; for example, by the gay boy porn use of handcuffs or by lashing their arms to an object. It may involve sexual attraction to women who are pregnant or appear pregnant, attraction to lactation, or attraction to particular stages of pregnancy such as impregnation or childbirth. Going back at least as far as the Christy twins in the 1970s, depictions of incest and particularly incest between twins has been a feature of gay pornography. Exhibitionist pornography features performers, usually female exposing themselves in public and spans simple flashing to public sex. It is also often mixed with other fetishes in practice, such as voyeurism, denial, etc. Gonzo porn is influenced by amateur pornography, and gay hentai it tends to use far fewer full-body/wide shots in favor of more close-ups naked milf . 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 secretary, often fake. Accepting that Eros is not always pretty, and may involve the forbidden or taboo - as with women pornography – forms part of the struggle with the good girl/bad girl or virgin-whore split in postmodern femininity. In many cases, that person is also aroused by smelling body parts that have a urine scent.