Prom Queen - S2-E20
Continuity mistake: When Blaine and Kurt are in Breadstix talking about Prom, the amount of soda in both of their glasses changes between shots.
Prom Queen - S2-E20
Continuity mistake: As Kurt and Dave are talking in front of Kurt's French class, a short girl with a brown ponytail enters the class twice.
Answer: The show is purposefully stylized and over the top. It is not designed to be an accurate, realistic representation of American high school. The idea that the glee club is so unpopular other students can literally throw garbage at them with impunity is an over-exaggeration of how glee club is considered "un-cool" compared to things like football. However, there is a second way of looking at it. The audience is simply never shown anyone getting into any trouble for throwing slushies. Just because we don't see it doesn't mean it never happened.
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