The genre is popular enough in Japan that it is even the subject of parody. Others consider the position to involve the man squatting over his reclined partner while the testicles are repeatedly raised and lowered into the mouth. Among fetishists, the pose of reluctance—the victimization of the cuckold—is a major element of the paraphilia. Testosterone discourages fat storage in these areas. In humans, females generally have more round and voluptuous buttocks, caused by estrogen that encourages the body to store fat in the buttocks, hips, and thighs. Key party A key party is a form of swinger party, in which male partners place their car and house keys into a common bowl or bag on arriving. Milking pornography features lactating women being milked or milking themselves . Cum shots typically do not appear in girl-girl scenes and orgasm is normally implied by utterances, cinematic conventions, or body movement. No causal relationship is known between masturbation and any form of mental or physical disorder. Before the enforcement of the Hays Code, some cartoon shorts contained humor that was aimed at adult audience members rather than children. The resulting consent and understanding is occasionally summarized in a written contract, which is an agreement of what can and cannot take place. Female masturbation involves the stroking or rubbing gay movies of a woman vulva, especially lesbian hentai her clitoris, with an index or middle fingers, or both. At these events, allegedly increasingly popular among adolescents, females wearing various shades of lipstick take turns fellating males in sequence, leaving multiple colours on their penises. In Japanese, the term describes any type of perverse or bizarre sexual desire or act; it does not represent a genre of work. Sadomasochistic scenes sometimes reach a level that appear more extreme or cruel than other forms of BDSM—for example, when a masochist is brought to tears or is severely bruised—and is occasionally unwelcome at BDSM events or parties.