The full-weight body-pressure, moisture, sex odors and darkness can be perceived as powerful sexual attractions or compulsions. In Japanese, the term describes any type of perverse or bizarre sexual hentai videos desire or act; it does not represent a genre of work. Patricia Hill Collins, an African-American writer, theorizes that this is derived from a stereotype that those of black descent are promiscuous, and their buttocks are objectified by porn as a result. Yaoi is anime or manga milf xxx that features gay males . 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. In the 18th and 19th centuries, some European theologians and physicians described it as heinous, deplorable, and hideous, but during the 20th century, these taboos generally declined. The term bondage describes the practice of Physical restraining. Reality and voyeur pornography, animated videos, and legally prohibited acts also young gay porn influence the classification of pornography. Shotacon : Similar to Lolicon, this genre involves prepubescent or under-aged boys naked celebrities between the ages 6–12. Some people get sexual pleasure by inserting objects, such as urethral sounds, into the urethra , a practice known as urethral play or sounding. Although there may be no connection between coprophilia and sadomasochism , the limited data on the former comes from studies of the latter. Interactive pornography, available in CD-ROM and DVD format, allows the viewer to select the particular acts performed at any one time, sometimes with the camera providing a first person view. These actors often play the top roles but this is not always the case, such as with Kristen Bjorn and some Bel Ami models. Some straight actors have started acting in gay porn only to be accused of being gay while others first step was to strictly do solo scenes. Among swinging couples, one of the two partners is often the driving force and the other is more passive-supportive of the addition of additional sex parties.