Ethnic pornography is a genre of pornography that gay movies features performers of specific ethnic groups, or depictions of interracial sexual activity. Others involve partners who naturally have a significant difference in size. It may also involve touching, rubbing, or pinching the nipples or other erogenous zones while masturbating. Softcore pornography generally contains nudity or partial nudity in sexually suggestive situations, but without explicit sexual activity, sexual penetration or extreme fetishism, while hardcore pornography may contain graphic sexual activity and visible penetration, including unsimulated sex scenes. The fetish centers around this fantasy portrayal. In September 2003 the BBC reported on the new dogging craze. Sexual scenarios may involve male domination, female submission, exhibitionism and erotic entertainment. Pornography can be classified according to the physical characteristics of the participants, fetish, sexual orientation, etc., as well as the types of sexual activity featured. Fisting, handballing, fist-fucking, brachiovaginal, or brachioproctic insertion is a sexual activity that involves inserting a hand into the vagina or rectum. Caro rejected that as being a necessary conclusion, stating that female fatty deposits on the hips improve individual fitness of the female, regardless of sexual selection. Similar to Freud idea of a fetish, Bhabha defines racial fetish to be a fixation on other races being not different, but lesser or mutilated versions of the white male. The stimulation may involve hands, fingers, everyday objects, sex toys or combinations of these. Strappado with rope and a spreader bar. The interaction between tops and bottoms—where physical or mental control of the gay hentai bottom is surrendered to the top—is sometimes known as power exchange, whether in the context of an encounter or a relationship. Often, slave contracts are big tit milf set out in writing to record the formal consent of the parties to the power exchange, stating their common vision of the relationship dynamic.