The concept of lesbian, to differentiate women with a shared sexual orientation, is a 20th-century construct. The consent and compliance for a sadomasochistic situation can be granted only by people who can judge the potential results. Heterosexual bareback sex, as opposed to sex with condoms, not only poses an increased risk of STIs, but for pregnancy as well. Tentacle rape or shokushu goukan is found in some horror or hentai titles, with tentacled creatures having sexual intercourse with female characters. The arousal from being desperate comes from the sensation of having a full bladder. A somewhat controversial ejaculation control technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just before ejaculating. The person receiving anilingus is regarded as the passive partner in the act, and the person performing anilingus is the active partner. Although interracial pornography theoretically can apply to depictions of sexual activity between performers of any different racial groups, the term is most commonly used for heterosexual sex acts between black and white performers. Transsexual pornography is a genre of what is viagra pornography. By Japanese law, the genitals of actors and actresses must be censored and up the mid-1990 so was the depiction of pubic hair. Lesbianism has been a theme in erotic art since at least the time of ancient Rome, and many regard depictions of lesbianism to be erotic. A few extremely flexible males can reach and stimulate their penis with their tongue or lips, and so perform autofellatio. Pornographic films present sexual fantasies and usually include erotically stimulating material such as nudity. Sadomasochism does not imply enjoyment through causing or receiving pain in other situations . Facial cum shots are currently regularly portrayed in pornographic films and videos, often as a way to close a scene. It is mutual consent that makes a clear legal and ethical distinction between BDSM and such crimes as sexual assault or domestic violence.