Oral sex pornography frequently features a person performing fellatio, and less frequently cunnilingus. Medical pornography involves sexualized medical, often fake, including gynecological pelvic examinations, rectal examinations, and pelvic hentai sex or gynecological ultrasounds. Participants who exert sexual control over their partners are known as dominants or tops while participants who take the passive, receiving, or obedient role are known as submissives or bottoms. For circumcised males, on whom the glans is mostly or completely uncovered, this technique creates more direct contact between the hand and the glans. The most common male masturbation technique is simply to hold the penis with a loose fist and then to move the hand up and down the shaft. Pro-am pornography is sub-genre of amateur pornography that refers to professionally made porn that features amateur actors/actresses, often appearing for the first time in a pornographic film. The most common type of erotic spanking is administered on the bare buttocks, but can also be combined with bondage, in order to heighten sexual arousal and feelings of helplessness. A related term used in the genre is the term cougar, which implies an older woman as predator. Sexual relations between women have been illustrated as well as narrated, but much of the written material from the early modern period has been destroyed. Some aspects of the research community distinguish between female ejaculation and what is colloquially known as squirting or gushing. Lying face down on a comfortable surface such as a mattress or pillow, the penis can be rubbed against it. Pornographic films horny milfs are typically categorized as either softcore or hardcore gay sex video pornography. A study of the condom usage habits of New Zealand sex workers said that they offered various safe sex alternatives to vaginal sex to clients who refused to wear a condom. 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.
