10 More Horror Movies Where Pranks Brutally Backfired

10. Girl House (2014)

In an unprecedented move, Trevor Matthews' Canadian slasher movie Girlhouse kicks off with the killer’s backstory and motives. No prizes for guessing that it all begins as a prank.

In,1988, two girls prank an overweight boy nicknamed Loverboy (Isaac Faulkner) by having him drop his trousers on the promise of a kiss, only to humiliate him when he actually follows through. In retaliation, Loverboy kicks one of the girls from her bicycle and throws her off a bridge to her death. Thus begins the plight of an innocent and the rise of a villain. 

And therein lies the real tragedy of this prank, because, while the initial consequences are certainly bad enough, it also engenders Loverboy's (now played by Slaine) descent into becoming a repressed, sexually deficient adult who gets his kicks by watching women online and occasionally stalking them IRL. That's right, he's an incel, in a time when the name and concept was just beginning to gain traction.

Chances are Loverboy would've turned out this way regardless, but there's no denying the ensuing carnage was sparked by this act of humiliation, as Loverboy stalks the titular girl's house (a compound full of cameras where girls act out viewers' fantasies - kind of like 2002's Demonlover but with more consent and less prestige) and lays waste to multiple victims.