Many of these activities might be based gay movies on rape. Women who adopt a lesbian identity share experiences that form an outlook similar to an ethnic identity: as homosexuals, they are unified by the heterosexist discrimination and potential rejection they face from their families, friends, and others as a result of homophobia. Some masturbate only using pressure applied to the clitoris without direct contact, for example by pressing the palm or ball of the hand against underwear or other clothing. Shotacon : Similar to Lolicon, this genre involves prepubescent or under-aged boys between the ages 6–12. The purpose of this kind of agreement is primarily to encourage discussion and negotiation in advance, and then to document that understanding for the benefit of all parties. Internationally, hentai is a catch-all term to describe a genre of anime and manga pornography. Such works have also often been subject to censorship and other legal hentai porn restraints to publication, display or possession. Studies have found that masturbation is frequent in humans of both sexes and all ages, although there is variation. Reading or viewing pornography, sexual fantasy or other erotic stimuli may lead to a desire for sexual release such as by masturbation. While wearing diapers, a diaper fetishist generally experiences a comforting feeling. Production of such films was profitable, and a number of producers specialised in their production. Special forms include erotic roleplay like ageplay, in which a difference in age, either real or enacted, formulates the background; or petplay. They signal the presence of estrogen horny milfs and the presence of sufficient fat stores for pregnancy and lactation. A spanking may be carried out with the use of a bare or gloved hand, or with any of a variety of implements, including a paddle, strap, hairbrush, feather duster or belt. The term has origins in the Greek language . The Girls Gone Wild series is one example. Being forced to wear diapers as a form of humiliation is sometimes a behavior encountered in sexual masochism.