The "Applause" singer is being sued by music producer and R&B singer Teddy Riley for half a million dollars plus punitive damages, according to TMZ.
Teddy produced Gaga's 2009 tune "Teeth," which was featured on her album The Fame Monster. In his lawsuit, Teddy claims to have been promised 25% of the writing fees, but that he hasn't been paid anything.
The Fame Monster has sold 1.56 million copies in the U.S. alone, and the song "Teeth" has charted in multiple countries.
Teddy himself has had a long career as both a producer and performer. He started performing in the '80s but is best known for having been a member of the '90s R&B group Blackstreet, who are famous for their 1996 hit, "No Diggity."
As a producer, Teddy has had phenomenal success as well. For example, he produced the Michael Jackson album Dangerous and co-wrote several of the songs of that album.
This is not the first time Lady Gaga has been on the receiving end of a lawsuit. Her former assistant sued her in 2011, alleging she was owed thousands of hours in unpaid overtime.
We'll have to wait and see if this new lawsuit takes a bite out of Gaga's finances. (Get it — "bite"? Because the song is called "Teeth"?)