AceShowbiz -

One of Lady GaGa's ex-boyfriends is unhappy that he was portrayed as a villain in her longtime friend's book. Luc Carl, a heavy-metal drummer, has threatened to sue Brendan Jay Sullivan who wrote a book about the superstar's early career and published it under HarperCollins.

In "Rivington Was Ours", Carl is described as someone who didn't have time for GaGa, "inattentive and possessive" and more. Sullivan wrote that GaGa would dye her "thick, dark, raven-haired Italian mane" blond just to impress Carl. However, Carl was a negative influence for her, controlling who she could talk to and where she could work while he was "distracted by a small coterie of drunk girls".

GaGa and Carl had been dating for three years before they broke up in 2008. Carl himself admitted in his memoir that he was not a good boyfriend for her. "I was f ** king miserable, and it wasn't her fault. It was my fault for being a drunk a ** hole. I would have left me, too," he wrote. GaGa previously admitted that she wrote the song "Judas" for her past bad romances, saying "I've had a lot of ex-boyfriends betray me, a**holes, we all have them."

Despite the confession, Carl sent Sullivan and HarperCollins a legal letter. Sullivan confirmed to Page Six, "GaGa told me herself that Luc told her early in her career, 'I hope you fail,' and that gave her the fire she needed at the time to fight for her dreams. Luc wasn't happy that I made him the villain of the piece. HarperCollins got a letter from him, he is threatening me and HarperCollins with a lawsuit."

GaGa is now dating "Chicago Fire" star Taylor Kinney and has declared her love for him. "It has been hard for me to find it, but I have found love. When you meet someone that's not intimidated by the amazing people that are around you [or] by the love that you receive - that's love," she told Fashion magazine.