The term pearl necklace is used by some because the drops of semen deposited by the man resemble a necklace of translucent white pearls. Hentai narrow Japanese usage and broad international usage are often incompatible. This is commonly called double vaginal penetration or double stuffing. For some people, non-penetrative sex is the primary sexual activity of choice above all others. In Japanese, the gay hentai term describes any type of perverse or bizarre sexual desire or act; it does not represent a genre of work. It contains graphic horny milfs sexual activity and visible penetration. Diaper fetishism, nappy fetishism or diaperism, is a sexual fetish in which a person feels a desire to wear or use diapers. Boots are seen as the perhaps most fetishistic of all footwear and boots may be the most popular fetish clothing attire. Internationally, hentai is a catch-all term to describe a genre gay sex video of anime and manga pornography. Standing up, a chair, the corner of an item of furniture, or even a washing machine can be used to stimulate the clitoris through the labia and clothing. Works in this genre may explore philosophical, political or social issues. Perhaps following the example set by gay pornography, they have become a popular subgenre within heterosexual pornography since the turn of the century, featuring both vaginal and anal ejaculations. A study of 164 males in Finland from two SM clubs found that 18.2% had engaged in coprophilia; 3% as a sadist, 6.1% as a masochist, and 9.1% as both. 18% of heterosexuals and 17% of homosexuals in the study pool had tried coprophilia, showing no statistically significant difference between heterosexuals and homosexuals. Lying face down one may use the hands, one may straddle a pillow, the corner or edge of the bed, a partner leg or some scrunched-up clothing and hump the vulva and clitoris against it. Exhibitionism: Becoming noticeably desperate or wetting oneself with the express purpose of being seen by strangers. These styles are much closer to the style of bondage scenes in mainstream television.