The porn industry and viewing public were shocked by the then-taboo spectacle of a white woman having sex with a black man. Both sexes sometimes apply lubricating substances to intensify sensation. 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. Pro-am pornography is sub-genre of amateur pornography that refers to professionally made porn that features amateur actors/actresses, often appearing for the first time in a pornographic film. Buttocks are sometimes emphasized in pornography, where they are often referred to as booty. Some men also enjoy anal stimulation, with fingers or otherwise, without any prostate stimulation. Dwarfs or midget pornography features performers who are dwarfs/midgets. Reality and voyeur pornography, animated videos, and legally gay movies prohibited acts also influence the classification of pornography. It is used, for example, at fertility clinics to stimulate sperm donors. The phrase buttered bun is sometimes used to refer to the owner of the orifice in question. The glans itself may widen and lengthen momporn as the stimulation continues, becoming slightly darker in colour, hentai porn while the gliding action of the foreskin reduces friction. In Canada, Teletoon offers up its own Teletoon at Night programming block. In the gay pornography industry, which uses amateurs as well as professional actors, the term gay-for-pay refers to actors labeled or believed to be straight but who engage in same-sex sexual activities for money. Some may keep their hand stationary while pumping into it with pelvic thrusts in order to simulate the motions of sexual intercourse. A related term used in the genre is the term cougar, which implies an older woman as predator. Bondage pornography specializes in the depiction of sexual bondage or BDSM activities as photographs, stories, movies, or drawings. The volume of semen that is ejaculated depends on several factors, including the male health, age, degree of sexual excitement, and the time since his last ejaculation.