In Japan, point of view pornography momporn is referred to as hamedori . Creampie pornography features ejaculation inside the vagina , mouth or rectum instead of the common cum shot, followed by the visible seeping or dripping of semen from the vagina, mouth or anus. Yaoi is anime or manga that features 3d hentai gay males . 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 gay boy porn tried coprophilia, showing no statistically significant difference between heterosexuals and homosexuals. When used as an alternative to penile-vaginal penetration, the goal may be to preserve virginity or to prevent pregnancy. Such works have also often been subject to censorship and other legal restraints to publication, display or possession. They may be noted for using risqué themes, graphic violence, sexuality or black comedy in a manner that is unsuitable for younger audiences. Top and dominant are widely recognized for those partner in the relationship or activity who are, respectively, the physically active or controlling participants. Mammary intercourse is known as titty-fucking, titfuck, or a titjob in the United States, as well as tit wank or French fuck in the United Kingdom - the latter term dating back to the 1930s; while a more jocular equivalent is a trip down mammary lane. In these research publications, it is suggested that real female ejaculation is the release of a very scanty, thick, and whitish fluid from the female prostate, while the squirting or gushing shown frequently in pornography is a different phenomenon, the expulsion of clear and abundant fluid, which has been shown to be a diluted fluid from the urinary bladder. 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. 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.