Katy Perry was offended by Russell Brand's good luck tweet before her Super Bowl performance on Sunday (01.02.15).
The 39-year-old comedian - who was married to the pop star from October 2010 until July 2012 - wished his ex-wife well before her half-time performance at the game between the New England Patriots and the Seattle Seahawks in Glendale, Arizona.
But Katy - who is dating fellow singer John Mayer - was reportedly unhappy that Russell chose to "involve himself" on the biggest night of her career.
A source told The Sun newspaper: "She couldn't believe he'd say that after everything he put her through.
"This was the man who, quite literally, destroyed her heart. He slagged her off publicly around the world.
"Then on the biggest night of her life professionally, he could not resist involving himself."
Ahead of the spectacle, Russell tweeted: "Super Bowl may be baffling to Brits but half time show will be amazing. Good luck KP. (sic)"
The 30-year-old singer performed a set that included 'California Gurls' and 'Teenage Dream', while Lenny Kravitz joined her for 'I Kissed A Girl'.
She also shared the stage with hip hop star Missy Elliott, who performed three of her own hits, 'Get Ur Freak On', 'Work it' and 'Lose Control'.
Katy ended her set with an eye-catching rendition of 'Firework', during which she flew around the stadium on a giant sparkler-shooting star.