Jennifer Lopez and Mariah Carey are at war over Nicki Minaj!
"Mariah considers Nicki to be more of a pest than anything, like a buzzing gnat," a source said.
"But it's Jennifer who really gets under her skin. They've always bad-mouthed each other, but Mariah hit the roof when she heard Jennifer called Nicki and offered to help her become the most popular American Idol judge.
"Jennifer is instructing Nicki on everything from how to treat contestants to what to wear. Mariah was so upset she called Jennifer directly and told her to butt out.
"It boils down to Mariah having always viewed Jennifer as a subpar singer and actress. And J. Lo thinks Mariah is stuck-up and has poked fun at her weight struggles. Mariah and Jennifer are now archenemies."