Madonna is reportedly furious with rapper MIA for giving the finger at their Super Bowl performance.
The Paper Planes singer joined Madonna on stage as a guest vocalist at Monday's game but shocked viewers when she stuck up her middle finger whilst singing the line: "I don't give a s**t," from Madonna's new track Give Me All Your Luvin'.
As the incident continues to grab headlines across the world, Madonna, 53, is said to be far from pleased, feeling it has detracted from their performance.
A source told The Sun newspaper: "Madonna wasn't impressed. She prides herself on professionalism.
"MIA did nothing similar in rehearsals. Nobody knew she was going to pull this stunt.
"Madonna wanted to put on a world-beating performance. But everyone ended up talking about this girl's middle finger."
According to a second source, MIA - real name Mathangi Arulpragasam - got carried away and acted on "adrenaline".
The source said: "She wasn't thinking. She was caught in the moment and she's incredibly sorry."
MIA, of Mitcham, south London, could face a fine according to TMZ.
A source told the US website she signed a contract which makes her liable to pay any penalties imposed by TV regulators.
A US$500,000 fine was imposed following Janet Jackson's "wardrobe malfunction" when she flashed a breast at the 2004 Super Bowl.
- BANG! Showbiz