Felching is a sexual practice involving the act of orally sucking semen out of the vagina or anus of one partner. Hermaphrodite, also known as herm, refers to pornography, typically hentai, that features persons with the genitalia of both sexes. The consensual submission of the submissive is sometimes demonstrated to others by symbols indicating his/her belonging to the dominant, such as wearing a collar, special tattoos, piercings, a very short haircut or a bald head. Production of such films was profitable, and a number of producers specialised in their production. As well as traditional attraction, the topic also incorporates feederism and gaining, where sexual gratification is obtained via the process of gaining body fat. This genre also features young gay porn male-on-male fellatio through a small hole made in a bathroom divider. Erotic spankings are commonly combined with other forms of sexual foreplay. Following World War II, during a period of social repression when governments actively persecuted homosexuals, women developed networks to socialize with and educate each other. Lolita pornography caters to ephebophiles. Medical pornography involves sexualized medical, often fake, including gynecological pelvic examinations, rectal examinations, and pelvic or gynecological ultrasounds. The cover can have hinges or be a separate part. Snowballing or snowdropping is the human sexual practice in which one person takes someone else semen into his or her mouth and then passes it to the mouth of the other, usually through kissing. Group sex pornography features at least two men and two women , usually more, who all perform sex acts on each other. They may regard it as an enhancing lesbian milfs element of their sex lives or as hentai movies their primary form of sexual activity. The industry generally refers to such films as adult films, which is part of adult entertainment. Examples of mentally oriented practices are education games, during which the dominant requires certain forms of behavior from the submissive.