“Nerdy Prudes Must Die” is just as outspoken and hilarious as its name suggests. It’s the fifth installment of the Hatchetfield series from StarKid Productions. Like its predecessors, it’s a horror-comedy musical set in the fictional town of Hatchetfield, except this time it’s a parody of 90s’ teen-slashers, complete with the high school stereotypes and questionable horniness.