Production of such films was profitable, and a number of producers specialised in their production. A person may be sexually penetrated horny milfs multiple times simultaneously. The term breast fetishism is also used to refer to cultural attention to female breasts and the sexuality they represent, with debate continuing as to whether the modern widespread fascination with breasts among heterosexual males in western societies is a sexual fetish. Being forced to wear diapers as a form of humiliation is sometimes a behavior encountered in sexual masochism. To avoid soreness from this resulting friction, some may prefer to use a personal lubricant, masturbation cream or saliva during masturbation. A lesbian is a female homosexual; a female who experiences romantic love or sexual attraction gay twink porn to other females. It is the most common form of sexual fetishism for otherwise non-sexual objects or body parts. A study of 164 males in Finland from two SM clubs found that 18.2% had engaged in coprophilia; 3% as a sadist, 6.1% as a masochist, and hentai sex 9.1% as both. 18% of heterosexuals and 17% of homosexuals in the study pool had tried coprophilia, showing no statistically significant difference between heterosexuals and homosexuals. The current public acceptance of celebrities with sex tapes is speculated by Joe Levy, executive editor of Rolling Stone, to be due to the easy availability of pornography, as well as couples more commonly making their own tapes due to the prevalence of video cameras. Group sex also occurs in populations of non-human animals such as bonobo apes and chimpanzees. The preference could be barefoot, high-heels, flip flops, and so on, depending on the fetishist. They signal the presence of estrogen and the presence of sufficient fat stores for pregnancy and lactation. Mammary intercourse is known as titty-fucking, titfuck, or a titjob in the United States, as well as tit wank or French fuck in the United Kingdom - the latter term dating back to the 1930s; while a more jocular equivalent is a trip down mammary lane.