Voyeur or peeping Tom pornography is usually more staged with the subjects aware of the cameras, sometimes openly including this exhibitionist awareness. In these cases, the appearance of an enlarged abdomen caused by obesity or overeating may be sufficient, or simply the suggestion of a protruding navel. Group sex can occur between naked milf people of all sexual orientations and genders. In the 1920s, Havelock Ellis reported that turn-of-the-century seamstresses using treadle-operated sewing machines could achieve orgasm by sitting near the edge of their chairs. Real jail or prison or police station shots or videos may violate laws in some countries. Sometimes, asymmetric and often intentionally uncomfortable positions are employed to heighten the psychological hentai sex impact of the bondage. The effect is to give the viewer the sense that they are experiencing the sex acts that they are watching, as opposed to simply watching others as a voyeur. The higher pay scale and profile within a production often leads to group scenes where a straight actor only tops. This is why video stores might consider stocking transgendered subject matter in the straight section, as some straight men will have passive or active sex with another man as long as their partner appears to look like a woman to them, to some minor or major degree. In gay pornographic movies, actors who identify themselves as heterosexual, but who nevertheless perform explicit sexual acts with other males on film do not face the same stigmas as the mainstream acting counterparts and indeed can rise quickly to being featured actors. Fistees who are more experienced may take two fists . Along with the penis, the scrotum is sensitive and considered to be an erogenous zone. It can also be heightened by the person saying that they have to urinate. Some productions are noted for sophisticated and/or experimental storytelling and animation techniques. Bestiality pornography involves the sexual attraction of humans to animals. This practice has a distinct videos porno gay effect of immobilization and pain.