In the 18th and 19th centuries, some European theologians and physicians described it as heinous, deplorable, and hideous, but during the 20th century, these taboos generally declined. Additionally, the buttocks give an indication of the shape and size of the pelvis, which impacts reproductive capability. They may regard it as an enhancing element of their sex lives or as their primary form of sexual activity. The industry generally refers to such films as adult films, which is part of adult entertainment. At the end of the evening the female partners would randomly select keys from the bowl and leave with that key owner. A related term anime hentai used in the genre is the term cougar, which implies an older woman as predator. The term pearl necklace is used by some because the drops of semen deposited by the man resemble a necklace of translucent white pearls. Use of the agreed safeword is seen by some as an explicit withdrawal of consent. The niche popularity grew significantly in the latter half of the first decade of the 2000s. Many transgender people regard the term shemale as offensive, arguing that it mocks or shows a lack of respect towards the gender identity and gender expression of transgender individuals; in this view, the term emphasizes the biological sex of a person and neglects their gender. It is typically animated pornography, as the legal age to be featured in a pornographic film in Japan is 18. Bukkake is a sex act portrayed in pornographic films, in which several men ejaculate on a woman, or another man. Today, religions vary in their views of gaysex masturbation; some view it as a spiritually detrimental practice, some porn milf see it as not spiritually detrimental, and others take a situational view. A study of 164 males in Finland from two SM clubs found that 18.2% had engaged in coprophilia; 3% as a sadist, 6.1% as a masochist, and 9.1% as both. 18% of heterosexuals and 17% of homosexuals in the study pool had tried coprophilia, showing no statistically significant difference between heterosexuals and homosexuals.
