"Daddy/boy" and "Daddy/girl" relationships occur in the BDSM world (though of course "Mommy/boy" and "Mommy/girl" scenes can happen too, and the players of any role can be of either sex).
Fairy-tale-type games are also almost a stereotype; imagine Little Red Riding Hood and the Big Bad Wolf.
That's not the meaning I'm going to use here, though.To people in the scene, infantilism means one of two things.It can mean the type of ageplay that involves roleplaying as a baby in one way or another (there are many variations), as I've already mentioned. Ageplay is a form of (usually) erotic roleplaying in which at least one participant plays the role of someone with a different age.The role you play is limited only by your imagination! I'm married to Tammy Jo Eckhart, whom some of you know, and I am into really good and really bad movies, science fiction, Tarot cards, writing, computers, languages, and infantilism.The "strict schoolmaster/mistress and naughty schoolboy/girl" scene is almost a BDSM stereotype.(Note that the schoolmaster/mistress role is probably a role in which the player plays a role that's older than their own age.) The "juvie hall warden and teen juvenile delinquent" scene is certainly heard of.It doesn't have to be present, but it can be: being treated like a child and condescended to, being called names like "diaper baby" or "sissy", or even just looking like a child because of the clothing and other "props" you have with you can be erotically humiliating for some. One might think that, since this is a presentation about erotic age roleplaying, sex would necessarily be an element.Well, that depends on what you mean by "sex." For someone with an ageplay fetish, a wonderful amount of erotic energy can be built up without any explicit sexual activity whatsoever (although this could still be called "sex" from one point of view).This is not to say that there can't be actual sexual activity in the scene; there certainly can and some players wouldn't scene without it.But for others explicit sex doesn't have a place in some ageplay scenarios, and they don't miss it.