Films teach every new generation of teenagers that sex is like a powerful roadside IED made out of shame and consequences that will explode and mangle their awkward, gangly bodies. Starting in the '70s, movies taught that the normal outcome of premarital sex is backwoods slashers, but with Careful What You Wish For, director Elizabeth Allen delivers a watered-down James M. Cain–style noir thriller warning kids that if they have sex they'll be framed for murder.
Horny teenage virgin Dougie (Nick Jonas), whose body is going through many important physical changes, is on vacation with his mom and dad. Next door to the family's lakeside house, the Harpers are moving in: Dermot Mulroney is Elliot, an unpleasant, middle-aged dude with a sweet car, a sick boat and an extremely young wife, Lena, played by eerie Daryl Hannah replicant Isabel Lucas.
Lena seduces Dougie during a thunderstorm after she locks herself out of the house and needs a big, strong man to break a window for her. At this point, the film forgets Dougie is a virgin as he plows through some implausibly agile and non-awkward sex scenes that do not reflect adolescent reality, but whatever. As their affair progresses, Dougie learns that Lena hates the abusive Elliot; when he dies under mysterious circumstances, Dougie helps Lena stage an accident scene. Allen attempts to build a sense of mounting anxiety via the increasing suspicions of a tenacious insurance investigator, unexpected testimony from eyewitnesses and Lena's squirrelly behavior, but pop-star Jonas is incapable of making simple facial expressions, let alone evincing existential dread.