Mayer, 36, has some very specific requests for the high-end hotels he stays in, but it's Perry, 29, that really pulls the diva card.
According to a new report from Life & Style, prior to his arrival, Mayer requests that an aged bottle of Laguvulin 16 scotch, water, soda and a fruit platter be placed in his room.
And Perry loves ranch dressing, because the "Roar" singer demands an entire bowl of it -- along with nearly two dozen other snacks, six types of drinks, a full-length mirror, a coffee maker and a director's chair!
"John and Katy get VIP treatment wherever they go," an insider told the magazine.
"It's usually all the same items for TV shows, backstage at concerts and hotels."
To find out more about celebrities and their odd demands, click here.