Greater economic and social freedom allowed them gradually to be able to determine how they could form relationships and families. Both forms of pornography generally contains nudity. The genres of pornography are based on the type of activity featured and the category of participants, for example mateur pornography is a category of pornography that features models, actors or non-professionals performing without pay, or actors for whom this material is their only paid modeling work. English adopts and uses hentai as a genre of pornography by the commercial sale and marketing of explicit works under this label. Pregnancy fetishism is a context where pregnancy is seen by individuals or cultures as an erotic phenomenon. This stop and go build-up, known as edging, can achieve even stronger orgasms. The wife who enjoys cuckolding her husband is frequently called a hotwife, gay hentai or a cuckoldress if the man is more submissive. Amateur porn has been called one of the most profitable videos gays and long-lasting genres of pornography. Films with risqué content commenced to be produced soon after the invention of the motion picture in the 1880s. The padding may also muffle noises from the outside, causing a relaxation effect and heightening their other senses. In addition to mainstream pornography, the popularity of facials has led to creation of its own niche market, like video series that specialize in showing the act. This may relate to fetishes such as voyeurism or cuckolding. Mutual masturbation can be practiced by males or females in pairs or groups with or without actually touching another person as indicated by the following examples of contact versus non-contact scenarios: Non-contact mutual masturbation Two people masturbating in the presence of each other but not touching. Such films continued to be produced but could only be distributed by underground channels. Sometimes special furniture is used, such as a queening stool or smotherbox. Incest mature milfs itself is largely taboo, and is a crime in many countries.