Another variant of reality pornography consists of normal couples that are filmed by professionals, in which case the only obvious distinction from amateur pornography is the higher quality of production, filming and editing. Mammary intercourse is said by Alex Comfort to produce mutual orgasm in women with sensitive breasts , and it was one of the nine substitute exercises for penetrative sexual activities, as detailed in the Paradis Charnels of 1903. The smotherbox is placed on a stable surface. Pornography is generally classified gay hentai as either softcore or hardcore pornography. 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. Transsexual porn star Wendy Williams has stated that transsexual porn is classified as Straight milf fuck Specialty. Especially popular in post-World War 2 Japanese culture. The person sat upon may be in bondage, sexually submissive, or simply held down by the body-weight of the other person. Bareback sex is physical sexual activity, especially gay cock sexual penetration, without the use of a condom. This category also includes pornographic home movies. The term soft crush refers to the more common fetish surrounding videos involving inanimate objects or small invertebrates being crushed, while the term hard crush refers to such videos involving larger animals with vertabrae, and arguably more pain-susceptible animals . Bhabha, Anne McClintock and Kobena Mercer. Pornographic films present sexual fantasies and usually include erotically stimulating material such as nudity. Other possibilities are possible, such as a man having sex with two women who are having sex with each other. Mutual masturbation is a sexual act where two or more people stimulate themselves or one another sexually, usually with the hands. A celebrity may allow such a recording to surface willingly, as part of a publicity stunt.