VIDEO : Rob Kardashian Should Blame Blac Chyna For His Weight Gain

In a sneak peek of Sunday's upcoming episode of Rob & Chyna, Chyna is seen being super mischievous! Rob Kardashian has been on a journey to lose weight for a while now and goes to check his progress on the scale. As he does, Chyna tells Rob to "stand very still" and she secretly places her foot on the scale as he weighs himself! He is baffled by the results! However, after he is obviously getting frustrated Chyna lets him go one more time without any tricks. Sneaky Chyna!