Bukkake, Gokkun, Omorashi, and tentacle erotica are few uniquely Japanese genres known to western viewers. Clothed female, naked male is a genre of erotica featuring one or more nude men and one or more clothed women. Reflective of its views on sexuality and culture, Japanese pornography delves into a wide spectrum of heterosexual, homosexual, nude milfs and transgender sexual acts in addition to unique fetishes and philias. The term discipline describes psychological restraining, with the use of rules and punishment to control overt behavior. Simultaneous penetration of the mouth and either the vagina or anus. Arousal may be triggered by seeing the body movements or facial expressions of that person. Especially popular in post-World War 2 Japanese culture. Using the term shemale for a transsexual woman often implies that she is working in the sex trade. The buttocks in human females thus contain more adipose tissue than in males, especially after puberty. Real enema shots or videos of true medical situations may violate privacy laws in some countries. There were also a very limited number of specialist fetish hentai movies magazines which videos gays featured images of bondage, such as the famous Bizarre magazine published from 1946 to 1959 by the pioneering fetish photographer John Willie, and ENEG Exotique magazine, published 1956-1959. Sexual scenarios may involve male domination, female submission, exhibitionism and erotic entertainment. Depictions of male and female masturbation are common in pornography, including gay pornography. As in B/D, the declaration of the Top/Bottom may be required, though sadomasochists may also play without any Power Exchange at all, with both partners equally in control of the play. Pornography in the early 2000s. Teacher and Student or Boss and Secretary pornography involves sexualized situations which take place between an authority figure, such as a teacher or boss, and an underling, such as a student or secretary, often fake. Bisexual DVDs sell much better online than in adult video stores, possibly due to customers in stores feeling embarrassed to buy them.