Britney Spears rocked the house Friday night, kicking off her two-year, 100-show "Piece of Me" Las Vegas residency in front of a packed and star-studded crowd.
But while Britney's theatrics had the likes of Adam Lambert and Miley Cyrus grinding, Katy Perry was seen doing her best McKayla Maroney impression.
Despite being in the front row, she could not have seemed less interested.
Granted, the spectacle of Britney live is not what it used to be ... but ouch.
The 29-year-old failed to tap a toe or shimmy her hips even when the "Toxic" singer belted out some of her biggest hits in the Planet Hollywood arena.
For the most part she just stared blankly holding her bag. At one point, Katy even checked her phone. At another point, she chatted up a male friend.
Like on top of John Mayer.