The term is typically used by the cinematographer within the narrative framework of a pornographic film, and since the 1970s has become a leitmotif of the hardcore genre. Sometimes one or hentai movies more fingers may be inserted into the vagina to stroke its frontal wall where the G-spot may be located. Some anthropologists and sociobiologists believe that breast fetishism derives from the breasts similarity to buttocks, horny milfs but instead provide sexual attraction from the front of the body. Such ejaculation can be done by mammary intercourse, or masturbation over the other person, or result from the withdrawal of the penis from a partner mouth as he is ejaculating following fellatio, irrumatio, or intercourse. Types of anal sex can also be a part of lesbian sexual practices. Bear features a combination of middle-aged, hairy or overweight males. Common positions include lying on back or face down, sitting, squatting, kneeling or standing. It is typically animated pornography, as the legal age to be featured in a pornographic film in Japan is 18. Some may keep their hand stationary while pumping into it with pelvic thrusts in order to simulate the motions of sexual intercourse. Content featuring videos gays male bisexuality has been a growing trend since the advent of internet pornography. As a form of non-penetrative sex, it can be done for its own enjoyment or as foreplay. Group sex most commonly takes place in a private sex party or semi-public swinger gathering, but may also take place at massage parlors or brothels or, in some jurisdictions, at purpose-built locations such as sex clubs. Yuri : Featuring two grown adult women in a homosexual/lesbian relationship. Crush pornography features objects being crushed by an actress or actor, who generally plays an overtly dominant role. Two women tapegagged and cuffed to iron bars Bondage and Discipline are two aspects of BDSM that do not seem to relate to each other because of the type of activities involved, but they have conceptual similarities, and that is why they appear jointly.