The hidden function of sexual role plays is largely related to the world of sexual paraphilias of criminal activity or sinful fantasies, in which the participation in sexual role play exempts a person engaged in perverted sexual activity from social legal sanctions. This is best illustrated by, for example, the common sexual role play when the imaginary teacher gets in sexual contact with one of his female students in a classroom (paedophilia), or sexual act takes place in some animal costume (zoophilia) or in the clothes of the opposite gender (transvestitism). Moreover, paraphilic perversities can turn up in whole complexity in some special games, of which the most known is the so-called adult baby game. There a group of paraphilias can be indulged, such as incest (sexual intercourse with the mother), paedophilia (sexual intercourse with an infant, infantophilia), and clothes fetish (wearing nappies) and some dirty practices such as urophilia (sexual arousal by urination) or even fecophilia (the deriving of sexual gratification from fantasies or acts involving feces). There are psychological dimension of this role play as well, if we think of the defencelessness of a baby, the perverse enjoyment of helplessness and powerlessness of sex client being treated by a prostitute or escort prostitute in the role of a caring mother (vulnerability of a subordinate, BDSM).
