This erotic noir is about as substantial as one of its female lead’s string bikinis, but it’s an enjoyable trifle nonetheless. Former popster Nick Jonas is Doug, a college-age kid whose lake-house vacation is enlivened by a hot new neighbor, Lena (Isabel Lucas). Lena is married to ill-tempered financier Elliott (Dermot Mulroney), who hires Doug to fix up his sailboat.

Putting aside their supposed age difference — Jonas is hardly a teen, while Lucas looks more like a Jonas Brothers fan than a cougar — the two generate sparks as they carry on a fateful clandestine affair.

Director Elizabeth Allen Rosenbaum enlists a solid supporting cast, especially Paul Sorvino as the town’s folksy sheriff and Kandyse McClure as a suspicious investigator. It’s no “Body Heat,” but “Careful What You Wish For” is a decent hat-tip to the sultry thrillers of the ’80s and ’90s.