Bukkake is a sex act portrayed in pornographic films, in which several men ejaculate on a woman, or another man. When used as an alternative to penile-vaginal penetration, the goal lesbian hentai may be to preserve virginity or to prevent pregnancy. Some people get sexual pleasure by inserting objects, such as urethral sounds, into the urethra , a practice known as urethral play or sounding. However, bisexual pornography is often placed near the gay section in adult video stores, since many consumers are gay men. In Japanese, the term describes any type of perverse or bizarre sexual desire or act; it does not represent a genre of work. The other person may do the same during or after. Evolutionary momporn psychologists suggest that rounded buttocks may have evolved to be desirable trait because they provide a visual indication of the woman youth and fertility. Boots are seen as the perhaps most fetishistic of all footwear and boots may be the most popular fetish clothing attire. Though there have been numerous gang bang pornographic gay movies films since the 1980s, they usually involved no more than half a dozen to a dozen men. Lesbian pornography typically features a wider range of appearances and body types than is typical of mainstream pornography. Most bisexual porn is made by small production companies rather than the major studios. Women who perform in lesbian pornography often do not consider themselves lesbian or bisexual. Reality and voyeur pornography, animated videos, and legally prohibited acts also influence the classification of pornography. It is also known colloquially as gushing or squirting, although these are considered to be different phenomena in some research publications. Group sex most commonly takes place in a private sex party or semi-public swinger gathering, but may also take place at massage parlors or brothels or, in some jurisdictions, at purpose-built locations such as sex clubs. Although there may be no connection between coprophilia and sadomasochism , the limited data on the former comes from studies of the latter.