The prostate gland is one of the organs that contributes fluid to semen. Another variant of reality pornography consists of normal couples that are filmed by professionals, in which case the only obvious distinction from amateur pornography is the higher quality of production, filming and editing. The genres of pornography are based on the type of activity nude milfs featured gay bear porn 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. In some scenes or relationships it may be impossible for consent to be withdrawn in the middle of a scene, or the bottom may have the ability to revoke consent for a relationship as a whole, but not for a particular scene. Some techniques which may work for one individual can be difficult or uncomfortable for another. A pornographic work is characterized as hardcore if it has any hardcore content, no matter how small. The original definition of dogging – and which is still a closely related activity – is spying on couples having sex in a car or other public place. Lucky Pierre is slang for a person performing both receptive and insertive anal and/or vaginal sex simultaneously during a threesome, being positioned between the two partners. Female ejaculation is the expulsion of fluid by the paraurethral ducts through and around the human female urethra during or before an orgasm. Real enema shots or videos of true medical situations may violate privacy laws in some countries. Transgender pornography features performers who cross-dress for sexual gratification, either for themselves or for their partners. Although pornography has usually focused on heterosexuality, due to the prevalence of the heterosexual orientation, explicit gay material has a long history as well, which reaches back to Greek antiquity, if not to prehistory. The term discipline describes psychological restraining, with the use lesbian hentai of rules and punishment to control overt behavior.