The term is a slang word that originated in the gay community and comes from the equestrian term bareback, mature milfs which refers to the practice of riding a horse without a saddle. Some BDSM practitioners prefer a code of behavior that differs from SSC and is described as risk aware consensual kink , indicating a preference for a style in which the individual responsibility of the involved parties is emphasized more strongly, with each participant being responsible for his or her own well-being. It is mutual consent that makes a clear legal and ethical distinction between BDSM and such crimes as sexual assault or domestic gay movies violence. Rape itself is a crime in many countries. 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 . There is also some evidence that pornography can be used to treat voyeurism. This technique may include the use of a simulacrum, or artificial vagina. Real jail or prison or police station shots or videos may violate laws in some countries. Masturbation has been depicted in art since prehistoric times and is mentioned and discussed in very early writings. The term discipline describes psychological restraining, with the use of rules and punishment to control overt behavior. In many cases, that person is also aroused by smelling body parts that have a urine scent. The padding may also muffle noises from the outside, causing a relaxation effect and heightening their other senses. Men and women may masturbate until they are close to orgasm, stop for a while to reduce excitement, and then resume masturbating. Various groups within society have considered depictions of a sexual nature immoral, labeling them pornographic, and attempting to have them suppressed under obscenity and other laws, with varying degrees of success. BDSM has become an umbrella term for certain kinds of erotic behavior between consenting 3d hentai adults.