Each participant may engage in any type of sex acts with one or both of the others, such as vaginal, anal or oral sex or mutual masturbation. Women in homosexual relationships responded to this designation either by hiding their personal lives or accepting the label of outcast and creating a subculture and identity that developed in Europe and the United States. Transgender momporn pornography features performers who cross-dress for sexual gratification, either for themselves or for their partners. A few extremely flexible males can reach and stimulate their penis with their tongue or lips, and so perform autofellatio. Commercialized pornography accounts for a nearly US0 billion worldwide industry for the production of various media and associated products and services. Femdom features BDSM scenes in which the dominant partner is female. Many gay fuck cultures describe pain as an aphrodisiac. Gloryhole pornography features women performing fellatio on unidentified men through a small hole made hentai sex in a bathroom divider. The term hentai is never used in this context in Japanese. Some do not use the diapers at all, for arousal, or bladder and bowel movements. Examples of heterosexual pornographic film series featuring creampies include Cream Filled Teens and Internal Cumbustion. Some women who engage in same-sex sexual activity may reject not only identifying as lesbians but as bisexual as well, while other women self-identification as lesbian may not align with their sexual orientation or sexual behavior; sexual identity is not necessarily the same as one sexual orientation or sexual behavior, due to various reasons, such as the fear of identifying their sexual orientation in a homophobic setting. Tentacle rape or shokushu goukan is found in some horror or hentai titles, with tentacled creatures having sexual intercourse with female characters. Since the 1980s, many practitioners and organizations have adopted the motto safe, sane and consensual, commonly abbreviated as SSC, which means that everything is based on safe activities, that all participants be of sufficiently sound/sane mind to consent, and that all participants do consent.