Sexual orientation Pornography features an increasing variety of combinations of actors by their sexual orientation such as lesbian, gay, bisexual, and transsexuals in addition to traditional heterosexual roles. Foot fetish pornography features heavy emphasis on the feet of the participants, either in combination with kissing and genital sex or in the context of acts such as trampling or crush fetishism. Adult animation is genre of animation geared towards adults and sometimes teens. Examples of heterosexual pornographic film series featuring creampies gay hentai include Cream Filled Teens and Internal Cumbustion. The Silent Duck, also called Duck-Billing, is the technique often used in which the person engaging in hand insertion shapes the hand to resemble a duck milf xxx beak. It is sometimes combined with BDSM features. The genres of pornography are based on the type of activity featured 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. Hardcore pornography is pornography that depicts penetration or extreme fetish acts, or both. Sigmund Freud considered foot binding as a form of fetishism. Celebrity sex tapes are amateur or professionally-made recordings of sex acts, as performed by a celebrity and their partner. The existence of such content in commercially available pornography is widely considered an urban legend. For circumcised males, on whom the glans is mostly or completely uncovered, this technique creates more direct contact between the hand and the glans. Since development and pronunciation of the buttocks begins at menarche and declines with age, full buttocks are also a symbol of youth. A somewhat gay cock controversial ejaculation control technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just before ejaculating. Irrespective of the legal or social view of pornography, it has been used in a number of contexts.