Inappropriate child sexual activity
Inappropriate child sexual activity is a buzzword used by sexophobes and antisexuals to damn any form of child sexual activity.
The use of terms such as "appropriate" or "inappropriate" are moral value judgments, and not the result of empirical scientific research into child sexuality.
Serious sexologists consider any form of sexual expression by humans to be a valid subject of study, without making value judgments based on whatever personal moral belief system the sexologist may ascribe to. Those who use the term "inappropriate" when describing human sexual behavior immediately disqualify themselves from being called "serious sexologists".
See also
List of deceptive and derogatory terminology directed at boylovers (which is as yet mostly a list of terms, each one needing to (eventually) be "explained" further in new articles).