It is also known colloquially as gushing or squirting, although these are considered to be different phenomena in some research publications. They further argue that setting a discrete line between safe and not-safe activities ideologically denies consenting adults the right to evaluate risks vs rewards for themselves; that some adults will be drawn to certain activities regardless of the risk; and that BDSM play—particularly higher-risk play or edgeplay—should be treated with the same regard as extreme sports, with both respect and the demand that practitioners educate themselves and practice the higher-risk activities to decrease risk. For circumcised males, on whom the glans is mostly or completely uncovered, this technique creates more direct contact between the hand and the glans. John Stagliano is considered to have started the gonzo pornography genre with his Buttman series of films. Sometimes one or more fingers may be inserted into the vagina to stroke its frontal wall where the G-spot may be located. Hardcore pornography is pornography hentai sex that depicts mature milfs penetration or extreme fetish acts, or both. Since development and pronunciation of the buttocks begins at menarche and declines with age, full buttocks are also a symbol of youth. The term sadomasochism is derived from the words sadism and masochism . The prostate gland is one of the organs that contributes fluid to semen. Sex parties may be organized to enable people to engage in casual sexual activity or for swinging couples or people interested in group sex to meet, but any gathering where sexual activity is anticipated can be called a sex party. The smotherbox is placed on a stable surface. A crush fetish is a fetish in which one is sexually aroused usually when someone crushes objects, food, and sometimes small animals gaysex with their body, usually under their foot, or when crushed oneself. These agreements are binding in the sense that the parties have the expectation that the negotiated rules will be followed.