The most common type of erotic spanking is administered on the bare buttocks, but can also be combined with bondage, in order to heighten sexual arousal and feelings of helplessness. Dwarfs or midget pornography features performers who are dwarfs/midgets. Some anthropologists and sociobiologists believe that breast fetishism derives from the breasts similarity to buttocks, but instead nude milfs provide sexual attraction from the front of the body. Though there have been numerous gang bang pornographic films since the 1980s, they usually involved no more than half a dozen to a dozen men. On May 27, 2010 the television program The Doctors discussed the topic with dozens of teens, parents, and professionals. Typically featured are hitting, choking, name-calling and hair-pulling. Bukkake pornography hentai porn involves a performer, usually female, onto whom several men or women ejaculate, usually on the face. They may regard it as an enhancing element of their sex lives or as their primary form of sexual activity. The porn industry and viewing public were shocked by the then-taboo spectacle of a white woman gay boy porn having sex with a black man. Since mammary intercourse is a non-penetrative sex act, the risk of passing a sexually transmitted infection that requires direct contact between the mucous membranes and pre-ejaculate or semen is greatly reduced. Its primary goal is sexual arousal in its audience. Irrespective of the legal or social view of pornography, it has been used in a number of contexts. Pornography is often distinguished from erotica, which consists of the portrayal of sexuality with high-art aspirations, focusing also on feelings and emotions, while pornography involves the depiction of acts in a sensational manner, with the entire focus on the physical act, so as to arouse quick intense reactions. The volume of semen that is ejaculated depends on several factors, including the male health, age, degree of sexual excitement, and the time since his last ejaculation. For example, in Australia it is rated Refused Classification .