Additionally, the buttocks give an indication of the shape and size of the pelvis, which impacts reproductive capability. Incest itself is largely taboo, and is a crime in many countries. These actors often play the top roles but this is not always the case, such as with Kristen Bjorn and some Bel Ami models. Bondage pornography specializes in the depiction of sexual bondage or BDSM activities as photographs, stories, movies, or drawings. Detective magazines, comic books and early fetish magazines In the early 20th century, Detective magazines covertly provided a way of publishing bondage imagery. Bukkake is a sex act portrayed in pornographic films, lesbian hentai in which horny milfs several men ejaculate on a woman, or another man. Sadomasochism is practiced in isolation relatively rarely, though some masochists report biting, pinching, or even stun-gunning themselves as a prelude to, or as part of, masturbation. Macrophilia is a fascination with or a sexual fantasy involving giants, more commonly expressed as giantesses . Multiple men and women Bisexual pornography features one woman and two men who all perform sex acts on each other. Solo pornography recognized with AVN Awards include the All Alone series and All Natural: Glamour Solos. However, various groups within society considered such depictions immoral, labelling them pornographic, and attempting to have them suppressed under obscenity laws, with varying degrees of success. Throughout history, women have not had the same freedom or independence to pursue homosexual relationships as men, but neither have they met the same harsh punishment as homosexual men in some societies. Typically featured are hitting, choking, name-calling and hair-pulling. Pro-am pornography is sub-genre of amateur pornography that refers to professionally made porn that features amateur actors/actresses, often young gay porn appearing for the first time in a pornographic film. For circumcised males, on whom the glans is mostly or completely uncovered, this technique creates more direct contact between the hand and the glans.