By Japanese law, the genitals of actors and actresses must be censored and up the mid-1990 so was the depiction of pubic hair. BDSM is a variety of erotic practices involving dominance and submission, role-playing, restraint, and other interpersonal dynamics. Kinbaku means tight binding Kinbaku-bi which literally means the beauty of tight binding. In the 1970s, the hardcore pornography genre introduced the stereotypical cumshot scene as a central element of the hardcore film, in which the male actor ejaculates in a way ensuring maximum visibility of the act itself. The first pegging scene appears to have hentai sex 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. Some productions are noted for sophisticated and/or experimental storytelling and animation techniques. A somewhat controversial ejaculation control technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just before ejaculating. Rough sex pornography is similar to pornography featuring sadomasochism, and typically features a Top who humiliates and/or degrades a Bottom while being physically violent towards them. One or more of the participants may engage in autoerotic sexual activity, such as masturbation, possibly without physical contact with the other participants. 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 over the glans, which depending on foreskin length, is completely or partially covered and then uncovered in a rapid motion. This is commonly called double anal or double gay cock stuffing. There may be more than two participants; both group sex and gang banging can be included. Insertion in pornography features women inserting various odd objects into their anus or vaginas. In the context of consensual erotic activities, sadism and momsex masochism are not strictly accurate terms; there is a significant difference from the medical or psychological gay male sex usage of both terms.