Demi Lovato was left visibly riled during her last ever appearance on The X Factor on Thursday night (19Dec13) after she was mocked in a video montage.
After announcing her departure from the judging panel after two years, the Heart Attack hitmaker took up her seat alongside Simon Cowell for the last time for the talent show's finale.
During the episode, host Mario Lopez reminded viewers of Lovato and Cowell's fickle relationship, and introduced a pre-recorded segment showing the star drinking a mysterious green liquid.
A voiceover claimed she had been downing "Annoying Juice" so she could irritate her boss, but the footage failed to raise a smile with the star, who quit booze after a stint in rehab for addiction issues in 2010.
During the footage, Lovato could be seen mouthing, "That was (messed) up", to her fellow judge Kelly Rowland.
The clearly angry star was then asked by Lopez what she thought of the tape, and replied through gritted teeth, "I think it's very, very clear since I don't drink anymore 'Annoying Juice' has become my new drink and I love it because I get to annoy Simon with it."
Lovato has quit the show after two seasons so she can concentrate on her own music career.