For a foot fetishist, points of attraction include the shape and size of the foot and toes , jewelry , treatments , state of dress , odor, and sensory interaction . It is a matter of subjective definition whether participation of a third person without physical contact constitutes a threesome. Rubber momsex pornography involves rubber, latex, and similar materials. Particularly, some pornography in this genre features butch women, who are almost never seen in mainstream pornography. The most successful animated features produced in the United States primarily for adult audiences were directed by Ralph Bakshi, including Fritz the Cat, Heavy Traffic and Coonskin. Medical pornography involves sexualized medical, often fake, including gynecological pelvic examinations, rectal examinations, and pelvic or gynecological ultrasounds. Studies among BDSM practitioners in the US have shown that about half of all men find the idea of bondage to be erotic; many women hentai sex do as well. A study of 164 males in Finland from two SM clubs found that 18.2% had engaged in coprophilia; 3% as a sadist, 6.1% as a masochist, and 9.1% as both. 18% of heterosexuals and 17% of homosexuals in the study pool had tried coprophilia, showing no statistically significant difference between heterosexuals and homosexuals. Testosterone discourages fat storage in these areas. Locks may be used to emphasize the submissive position or the submissive hands may be fastened above his head to the box. The glans itself may widen young gay porn and lengthen as the stimulation continues, becoming slightly darker in colour, while the gliding action of the foreskin reduces friction. Pegging films include Strap It On , Babes Balling Boys , Strap Attack, Strap-on Sirenz, Strap-on Chicks, Boss Bitches , various movies produced by LEDA Studios, and San Francisco-based Men In Pain. Some may pursue fantasies that are concerned with the circumstances in which a subject may give birth, or to the conditions to which the pregnant subject may find themselves acting upon, such as approaches to mobility, sleeping, and dressing.