John Stagliano is considered to have started the gonzo pornography genre with his Buttman series of films. Terminology for roles varies widely within the various BDSM subcultures. Sometimes one or more fingers may be inserted into the vagina to stroke its frontal wall where the G-spot may be located. Hamedori is a genre of Japanese pornography in which a male adult video actor or director serves as the camera operator. If dramatic skills are not involved, a performer in a porn film may also be called a model. Typically featured are hitting, choking, name-calling big tit milf and hair-pulling. What seems clear from the historical record is that much of the lesbian material in pornographic texts was intended gay boy porn for a male readership. Interactive pornography, available in CD-ROM and DVD format, allows the viewer to select the hentai sex particular acts performed at any one time, sometimes with the camera providing a first person view. Threesome can also refer to a love triangle, a three-way romantic relationship. Evolutionary psychologists suggest that rounded buttocks may have evolved to be desirable trait because they provide a visual indication of the woman youth and fertility. The original definition of dogging – and which is still a closely related activity – is spying on couples having sex in a car or other public place. Incest itself is largely taboo, and is a crime in many countries. Sexologist Alfred Kind suggested that the buttocks is the primary sexual presentation site in primates. The full-weight body-pressure, moisture, sex odors and darkness can be perceived as powerful sexual attractions or compulsions. 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. It has also been recommended as a form of foreplay or safer sex. As a result, little in history was documented to give an accurate description of how female homosexuality is expressed.