Masturbation involves touching, pressing, rubbing or massaging a person genital area, either with the fingers or against an object such as a pillow; inserting fingers or an object into the anus ; and stimulating the penis or vulva with an electric vibrator, which may also be inserted into the vagina or anus. Pleasure for the giver during anilingus is usually based more on the principle of the act. This is why video stores might consider stocking transgendered subject matter in the straight section, as some straight men will have passive or active sex with another man as long as their partner appears to look like a woman to them, to some minor or major degree. Kinbaku is a Japanese style of bondage or BDSM which involves tying up the bottom using simple yet visually intricate patterns, usually with several pieces of thin rope . Studies indicate that anilingus is a rare sexual practice between women. With second wave feminism and growth of scholarship in women history and sexuality in the 20th century, the definition of lesbian broadened, sparking a debate about sexual desire as the major component to define what a lesbian is. Ethnic pornography is a genre of pornography that features performers of specific ethnic groups, or depictions of interracial sexual activity. Softcore pornography generally contains nudity or partial nudity in sexually suggestive situations, but without explicit sexual activity, sexual penetration or extreme fetishism, while hardcore pornography may contain graphic sexual activity and visible penetration, including unsimulated sex scenes. BDSM has become an umbrella term for certain kinds of erotic behavior between consenting adults. Futanari, Hentai females with a milf fuck penis. Erotic literature and pornographic 3d hentai films have been devoted to the sexual uses of glory holes. However the genre remains a gay movies very small proportion of the pornographic DVD market; for example at porn retailer HotMovies. In general, softcore pornography is pornography that does not depict explicit sexual activity, sexual penetration or extreme fetishism.