Currently, animated television series aimed at adults are some of the most popular and critically acclaimed forms of entertainment. Sloppy seconds is a slang phrase for when a man has sexual intercourse with another person who already has received another man penis in the relevant orifice and is therefore wet or sloppy. The naked milf consent and compliance for a sadomasochistic situation can be granted only by people who can judge the potential results. The sub-genres usually conform to certain conventions, and each may appeal to a particular audience. There were also a very limited number of specialist fetish magazines which featured images of bondage, such as the famous Bizarre magazine published from 1946 to 1959 by the pioneering fetish photographer John Willie, and ENEG Exotique magazine, published 1956-1959. Although pornography has usually focused on heterosexuality, due to the prevalence of the heterosexual gay cock orientation, explicit gay material has a long history as well, which reaches back to Greek antiquity, if not to prehistory. The effect is to give the viewer the sense that they are experiencing the sex acts that they are watching, as opposed to simply watching others as a voyeur. It may also involve touching, rubbing, or pinching the nipples or other erogenous zones while masturbating. Boot fetishism is a sexual fetish dedicated to boots. Lucky Pierre is slang for a person performing both receptive and insertive anal and/or vaginal sex simultaneously during a threesome, being positioned between the two partners. Can also include auto-fellatio, or performing oral sex on oneself. Men and women may masturbate until they are close to orgasm, stop for a while to reduce excitement, and then resume masturbating. Pornography is generally classified as either softcore or hardcore pornography. Clothed female, naked male is a genre of erotica featuring one or more nude men and hentai movies one or more clothed women. While bondage is a very popular variation within the larger field of BDSM, it is nevertheless sometimes differentiated from the rest of this field.