Pornographic films present sexual fantasies and usually include erotically stimulating material such as nudity. Lesbianism has been a theme in erotic art since at least the time of ancient Rome, and many regard depictions of lesbianism to be erotic. Pornography may be presented in a variety of media, including books, magazines, postcards, photographs, sculpture, drawing, painting, animation, sound recording, film, video, and video games. These agreements are binding in the sense that the parties have the expectation that the negotiated rules will be porn milf followed. The buttocks in human females thus contain more adipose tissue than in males, especially lesbian hentai after puberty. A celebrity may allow such a recording to surface willingly, as part of a publicity stunt. Bobbi S. Some do not use the diapers at all, for arousal, or bladder and bowel movements. A few extremely flexible males can reach and stimulate their penis with their tongue or lips, and so perform autofellatio. It is sometimes combined with videos gays BDSM features. Celebrity sex tapes are amateur or professionally-made recordings of sex acts, as performed by a celebrity and their partner. Currently, animated television series aimed at adults are some of the most popular and critically acclaimed forms of entertainment. Interracial pornography typically employs ethnic and racial stereotypes in its depiction of performers and many of interracial pornographic films still include racial stereotypes, although the segregation of actors by race has diminished considerably. As of 2013, little analysis of this paraphilia has been reported in medical literature. It is used, for example, at fertility clinics to stimulate sperm donors. The wife who enjoys cuckolding her husband is frequently called a hotwife, or a cuckoldress if the man is more submissive. As in B/D, the declaration of the Top/Bottom may be required, though sadomasochists may also play without any Power Exchange at all, with both partners equally in control of the play. Entacle erotica describes a type of pornography most commonly found in Japan which integrates traditional pornography with elements of bestiality and a fantasy, horror, or science-fiction theme.