Female dominance refers to BDSM relationships and BDSM scenes in which the dominant partner is female. In the fetish cuckolding subculture, it is most common for the female to take on the sexually dominant role and the male the submissive role, however, female subs, sometimes referred to as cuckqueans, also exist. Bondage/BDSM Bondage pornography features performers tied up or constrained gay sex video in various gay hentai ways. 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. Examples include the Girls Gone Wild and Girls Who Like Girls Series. As of 2013, little analysis of this paraphilia has been reported in medical literature. The momporn concept of lesbian, to differentiate women with a shared sexual orientation, is a 20th-century construct. Fisher said that perhaps, the fleshy, rounded buttocks attracted males during rear-entry intercourse. If ejaculation is onto the other person face it can be called a facial. Normal quantities of ejaculate range from 1.5 to 5.0 milliliters . Stimulating the prostate from outside, via pressure on the perineum, can be pleasurable as well. It is sometimes combined with BDSM features. Common positions include lying on back or face down, sitting, squatting, kneeling or standing. There is no singular or archetypical behavior; therefore, a wide range of thought patterns and behaviors exist, but all tends to be a harmless and efficacious release from some kind of pressure. Most soft crush fetishists avoid being placed under the same label as hard crush fetishists, believing that crush films with larger animals give the entire group a bad label. It is also known colloquially as gushing or squirting, although these are considered to be different phenomena in some research publications. Double Stuffed , Double Vaginal , or Double Anal pornography involves the penetration of one orifice by two penises or other objects. The range of its individual characteristics is thereby wide.