A common delusion afflicting the self-styled "nice girl" (who may be either male or female), which consists of the mistaken belief that he/she is soooo superior to the "great unwashed" masses that he/she is excused from the indignity of being subject to the same natural bodily functions as the rest of us. One specific sense of the word denotes sexual frigidity -- i.e., "nice girls" don't have orgasms; they only submit to sexual intercourse in order to fulfill their duty to God and Country.
The girl acts as though she had a Tastee Freez dispenser up her butt. Pretends the thought of having sex has never entered her mind. Yeah, right, and nice girls shit ice cream.