Jennifer Lopez (J-Lo to her fans, Jenny from the block to her friends) serves as producer on this cuckoo in the nest thriller; playing the kind of role you’d suspect she’d taken in desperation, or to honour the demands of a blackmailer, were it not for that ominous, baffling credit. Fer-Pez plays Claire, an English Lit teacher (we know because she has a model of Shakespeare’s globe on her desk) that’s feeling lonely following the betrayal of her cheating shit husband, John Corbett.

With hubby shown the door but determined to worm his way back into the affections of the nni-ope and whiny son Ian Nelson, Jenny consents to father and offspring going away for the weekend, leaving her vulnerable to the jailbait physique of neighbour’s nephew, Ryan “Kit Musculature” Guzman. Guzman’s a literary tourist, interested in different types of globes to his teacher, and naturally the pair, left to their lust, have coyly shot intercourse. Unfortunately, in keeping with Hollywood’s second law of female representation, an older woman, even one possessing the J-Legs and J-behind of J-Lo, must be punished for sexual yearnings, and so Guzman, unalert to his one night stand’s shame, pushes for more, only to flip on a dime and become a fully deranged psychotic when Lopez vetoes an affair.

Rob Cohen, whose career has been in freefall since the likes of xXx (his last effort was the Razzie baiting Alex Cross) has fashioned, if fashioned isn’t too strong a word (it is) a piece of pure schlock that forsakes suspense and subtlety for a rote slab of mistake-that-follows-you-home hokum. From the moment J-Lo acts as tea cosy to Guzman’s member the trajectory is painfully clear. Kit, channeling Rebecca De Mornay, tries to turn Jennifer’s kid against her, sows discord amongst the family, sets up unfortunate accidents and trains his sights on offing Jenny’s suspicious friend, in this case Kristin Chenoweth (doubling for The Hand that Rocks the Cradle’s Julianne Moore). Unfortunately, Cohen fails to embellish this well-worn plot with anything like the kind of madness that would be required to offset its mechanical composition.

Adam Wingard’s recent The Guest showed that if you’re prepared to unzip your fly and flop out, you can have a lot of fun with this homewrecker formula. A family unit under threat invites invention, both in the scale of the villainy and the absurdity of the violence, but Cohen’s got nothing to offer us but Guzman’s wood, J-Lo’s pensive puss and a script that appears to have been torn from the sample appendix in a how not to write a screenplay manual. Ultimately we’re left counting the minutes to the lunatic’s demise and the inevitable family restoration, our faith in intergenerational relationships dangerously compromised.