That's nothing unique to legislation surrounding sex. Rebranding creationism to "intelligent design" and "teach the controversy" are great examples of disingenuous legislation attempting to create precedent and chip away at at issues in the background. In fact, I'd go so far as to say that things like literacy tests and poll taxes were such examples. It's standard fare for the course in politics. Law is one of those areas where the "slippery slope" argument does actually reflect reality.