It may also involve touching, rubbing, or pinching the nipples or other erogenous zones while masturbating. Pornography can be classified according to the physical characteristics of the participants, fetish, sexual orientation, etc., as well as the types of sexual activity featured. Bukkake, Gokkun, Omorashi, and tentacle erotica are few uniquely Japanese genres known to western viewers. It is mutual consent that makes a clear legal and ethical distinction between BDSM and such crimes as sexual assault or domestic violence. High heel pornography involves women or men dressed in high heeled shoes. Within a BDSM or D/s context, facesitting can be an especially intense form of erotic humiliation. When sexual activity is centered on one of the threesome, then the activity may be described as a gang bang of the person. Interest in BDSM can range from one-time hentai movies experimentation to a lifestyle. Sometimes, asymmetric and often intentionally uncomfortable positions are employed to heighten the psychological impact of the bondage. Real jail or prison or police station shots or videos may violate laws in some countries. Especially popular in post-World War 2 Japanese culture. Hentai is the various forms of Japanese pornography, including H-manga, H-anime, and H-computer games. In some areas, there are laws stating it is not legally possible to consent to be killed, and elsewhere it may still be legally dubious . Initially, few animation studios in the United States attempted to produce momporn animation for adult audiences, but later examples of animation produced for adults would gain mainstream attention and success. Caro rejected that as being a necessary conclusion, stating that female fatty deposits on the hips improve individual fitness of the female, regardless of sexual selection. Also see POV. Bukkake videos are a relatively prevalent niche in contemporary pornographic films. In general, softcore pornography is pornography that does not depict gay boy porn explicit sexual activity, sexual penetration or extreme fetishism.