In general, BDSM play is usually structured such that it is possible for the consenting partner to withdraw his or her consent during a scene; for example, by using a safeword that was agreed on in advance. Double Stuffed , Double Vaginal , or Double Anal pornography involves the penetration of one orifice by two penises or other objects. 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. Pornography is often distinguished from erotica, which consists of the portrayal of sexuality with high-art aspirations, focusing also on feelings and emotions, while pornography involves the depiction of acts in a sensational manner, with the entire focus on the physical act, so as to arouse quick intense reactions. It is also known colloquially as gushing or squirting, although these are considered to be different phenomena in some research publications. Internationally, hentai is a catch-all term to describe a genre of anime and manga pornography. Femdom features BDSM scenes in which the dominant 3d hentai partner is female. Sexual relations between women have been illustrated as well as narrated, but much of the written material from the early modern period has been destroyed. Particular areas and processes of the body that change during pregnancy may also become the focus of psychological investment, but nudity or sexual activity is not always essential, and in some cases actual pregnancy is not necessary to invoke arousal. BDSM communities generally welcome anyone with a non-normative streak who identifies momporn with the community; this may include cross-dressers, extreme body mod enthusiasts, animal players, latex or rubber aficionados, and others. Some straight actors have started acting in gay porn only to be accused of being gay while others first step was to strictly do gay sex video solo scenes. It is sometimes combined with BDSM features. Boots are seen as the perhaps most fetishistic of all footwear and boots may be the most popular fetish clothing attire.