Watch out, Rob Kardashian! Kim and Khloe have a plan to get you back into shape: reverse psychology.

In a preview of Sunday night’s episode of Keeping Up With The Kardashians, Rob’s older sisters plot to lock their little brother in a room and give him nothing but “burgers and fries and pizza.” Their theory? That “he’ll get so sick he’ll be like, ‘I can never eat this food again,’” explained Khloe while munching away on a salad.

Sounds a bit like cruel and unusual punishment to us, but hey, we’re not part of the Kardashian fam.

Rob’s already working to shed the weight (according to Rob himself, he got up to around 220 pounds by the time the dust settled on his relationship with Rita Ora). And now that pregnant sister Kim’s spilled the beans that Rob has stretch marks — thanks sis! — we’re sure he’s even more committed to hitting the gym.

The “lock him and leave him” diet scheme is only the latest in the Kardashians’ crazy antics. Last week’s premiere episode featured Khloe buying sister Kourtney sex toys to scare boyfriend Scott Disick out of his backdoor fantasies. Even more unbelievable: it worked!

Source: Us Magazine