It is typically animated pornography, as the legal age to be featured in a pornographic film in Japan is 18. Sadomasochism refers to the aspects of BDSM surrounding the exchange of physical or emotional pain. The term breast fetishism is also used to refer to cultural attention to female breasts and the sexuality they represent, with debate continuing as to whether the modern widespread fascination with breasts among heterosexual males in western societies is a sexual fetish. Ass to mouth is a slang term primarily used to describe the withdrawal of a penis from the receptive partner anus followed by the immediate insertion into the receptive partner mouth. Particularly, some pornography in this genre features butch women, who are almost never seen in mainstream pornography. New swinging couples often choose a soft swap before they are comfortable with a full swap, although many couples stay soft swap for personal reasons. Sadomasochistic scenes sometimes reach a level that appear more extreme or cruel than other forms of BDSM—for example, when a masochist is brought to tears or is severely bruised—and is occasionally unwelcome at BDSM events or parties. A 2009 study found that heterosexual male fat admirers preferred females that were clinically overweight and rated both overweight and obese women more positively than slighter individuals. The term has origins in the Greek language . Cartoon pornography depicts illustrated or animated fictional characters milf fuck in erotic and sexual situations. The initialism BDSM includes psychological and physiological facets: Bondage & Discipline Dominance & Submission Sadism & Masochism Types of Play This model for differentiating among these three aspects of BDSM is increasingly used in literature today. Penetration may involve use of fingers, gay bear porn toes, sex toys, or penises. Certain websites have begun providing bondage gay hentai videos and photographs featuring the kidnapping roleplay, which has been largely the hallmark of detective style bondage magazines.