Patricia Hill Collins, an African-American writer, theorizes that this is derived from a stereotype that those of black descent are promiscuous, and their buttocks are objectified by porn as a result. Tentacle erotica can be consensual, but frequently contains elements of non-consensual sex. These actors often play the top roles but this is not always the case, such as with Kristen Bjorn and some Bel Ami models. Fisher said that perhaps, the fleshy, rounded buttocks attracted males during rear-entry intercourse. Content featuring male bisexuality has been a growing trend since the advent of internet pornography. Diaper fetishism is totally independent from pedophilia as the wearer derives pleasure only from the diaper and/or use of it. The naked appearance of actress Demi Moore in the advanced stage of pregnancy on the cover of Vanity Fair magazine in 1991 marked the beginning of a period which has since seen pregnancy presented by celebrities as a glamorous state of living, while also creating a market for photographers to produce images of pregnant mothers, and for fashion stylists to introduce pregnancy styling to their business. Most bisexual porn is made by small production companies rather than the major studios. Urolagnia is a form of salirophilia in which sexual excitement is associated with the sight or thought of urine or urination. Spanking can be administered in a number of spanking naked milf positions. Felching is a sexual practice involving the act of orally sucking semen out of the vagina or anus of one partner. Bondage websites and bondage imagery in mainstream pornography As of 2003, specialist bondage magazines were mostly displaced by the availability of bondage material on the World Wide Web, and the presence of bondage imagery in mainstream pornographic lesbian hentai magazines such as Nugget and Hustler Taboo magazine. The name was coined from the title of the controversial gay twink porn book. Rape pornography features performers simulating rape. The glans itself may widen and lengthen as the stimulation continues, becoming slightly darker in colour, while the gliding action of the foreskin reduces friction.
