The fetish is called paraphilic infantilism or adult baby syndrome. It's about regressing to infancy, drinking from baby bottles, wearing diapers, enjoying "gentle nurturing" or scoldings and "humiliating experiences" (from Wiki). All this is sexual -- for some. A store called Tykables that sells adult baby syndrome paraphernalia has opened in a Chicago suburb. Oh, yes, and this is different from pedophilia, so don't confuse the two ... Read Huffington Post article about Tykables here.