The term bareback is used less frequently in the heterosexual community. Central to the typical MILF narrative hentai movies is an age-play dynamic of older women and younger lovers. A smotherbox has two openings. The term hamedori came into use about 1988–1989, but it was only a small niche area until it was popularized at V&R Planning by director Company Matsuo. Other forms of anal sex include fingering, the use of sex toys for anal penetration, oral sex performed on the anus , and pegging. The pornography is geared towards men; hence the word bisexual refers to the men rather than the woman. The essence of voyeurism horny milfs is the observing but may also involve the making of a secret photograph or video of the subject videos gays during an intimate activity. Spanking or whipping pornography involves spanking or whipping, generally of the buttocks, with the hand or with other objects such as belts, switches, paddles, brushes, or whips. Exhibitionist pornography features performers, usually female exposing themselves in public and spans simple flashing to public sex. Felching involves drinking recently ejaculated semen from the vagina or anus. With second wave feminism and growth of scholarship in women history and sexuality in the 20th century, the definition of lesbian broadened, sparking a debate about sexual desire as the major component to define what a lesbian is. Various groups within society have considered depictions of a sexual nature immoral, labeling them pornographic, and attempting to have them suppressed under obscenity and other laws, with varying degrees of success. The shocker accomplishes this using several fingers of one hand. To tea bag is a slang term for the sexual act of a man placing his scrotum in the mouth of a willing sexual partner for pleasure or onto the face or head of another person. Voyeur or peeping Tom pornography is usually more staged with the subjects aware of the cameras, sometimes openly including this exhibitionist awareness. In recent years, Japanese films of this genre have become more common in the USA and Europe although it still remains a small, fetish-oriented part of the adult film industry.