Some restrict a policy of panties/nipple tape for females and some allow full nudity with explicit momporn sexual interaction allowed. Incest pornography can feature gay hentai actual relatives, but the main type of this pornography simply uses actors of similar looks to suggest family relationship. The nipples are erogenous zones, and vigorous stimulation of them during masturbation usually causes the penis to become erect more quickly than it would otherwise. Guro or Gore is a genre of Japanese pornography involving blood, gore, disfiguration, violence, mutilation, urine, enemas, or feces. Group sex can occur between people of all sexual orientations and genders. However, the tradition of bondage magazines continues in the form of art books of bondage photographs, published by mainstream publishers such as Taschen. Making a pearl necklace is one of the activities that sex workers use as safe sex alternatives for people who refuse to wear condoms. Unlike erotic films, pornographic films contain explicit sexuality and do not claim any artistic merit. The related term twinkle-toes, which implies that a man is effeminate, tends to be used in a derogatory manner. Men and women may masturbate until they are close to orgasm, stop for a while to reduce excitement, and then resume masturbating. Some do not use the diapers at all, for arousal, or bladder and bowel movements. Kinbaku means tight binding Kinbaku-bi which literally means gaysex the beauty of tight binding. Although pornography has usually focused on heterosexuality, due to the prevalence of the heterosexual orientation, explicit gay material has a long history as well, which reaches back to Greek antiquity, if not to prehistory. One-sided male nudity can also arise when a male disrobes as part of a male striptease. Bisexual DVDs sell much better online than in adult video stores, possibly due to customers in stores feeling embarrassed to buy them. For other diaper fetishists, simply wearing a diaper, the bulking feeling and crinkling sounds associated with it, is enough to cause the fetishist a form of erotic pleasure or sexual arousal.