In this KUWTK throwback clip we look at the hilarious moment Kim pranked her unsuspecting brother by donning a full disguise and trying to hit on him. The Kardashians are famed for their wild antics, tight-knit family unit, and hilarity. Keeping Up With the Kardashians frequently saw the family playing pranks on each other. Kim Kardashian has managed to prank siblings before, like her classic ‘Bachelorette’ prank. We look back at one of the earlier seasons in which Kim pulls a hilarious prank on brother Rob, where she dresses up as ‘Cynthia’ and tries to hit on him. ‘Cynthia’ thinks Rob is ‘ju…