Dominance and submission is a set of behaviors, customs and rituals relating to the giving and accepting of control of one individual over another in an erotic or lifestyle context. It can also be heightened by the person saying that they have to urinate. Scenes of multiple penetration are common in pornography. Solo pornography features performers masturbating. A queening stool is a low seat which fits over the submissive face and contains an opening to allow oral-genital and/or oral-anal stimulation of the domme while seated. This yields a view that would not be gay hentai obtainable directly through the eyes of a person while experiencing the sex act. 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. Other popular implements are canes, riding crops, whips, switches, birches, sneakers, rolled-up newspapers, rulers or martinet. There are currently no known laws forbidding the crushing of objects and insects, however the production or trade of crush erotica involving live vertebrates is condemned by animal rights activists and is illegal in many countries, including the United States and Great Britain. Ethnic pornography is a genre of pornography that features performers of specific ethnic groups, or depictions of interracial sexual activity. It generally contains nudity or partial nudity in sexually suggestive situations. In general, softcore pornography is pornography that does not depict explicit sexual activity, sexual penetration or extreme fetishism. In straight pornography, intercourse is often followed by a gay cock facial, pearl necklace or other visible ejaculation. Social attitudes towards the discussion and presentation of sexuality has become more tolerant and legal definitions of obscenity have become more limited, leading to an industry for the production and consumption of pornography in the latter half of the 20th century. Some couples use a threesome as a way to develop a mature milfs love triangle .