Kelly Clarkson and Carrie Underwood are allegedly feuding with each other in private. And what some people don’t know is that they’ve also been clashing over their music.

An unnamed source told Globe that Clarkson and Underwood are trying to conceal the truth about their relationship because they know that it’s not a good look for their career. After all, they are both products of the same singing reality TV competition, American Idol.

“They may say there’s been no feud between them but anyone who knows them will tell you, they’re not friends, nor will they ever be. The bottom line is, that Carrie and Kelly don’t like each other much, and the constant comparisons drive them both crazy. The only similarity between them is they won their seasons on American Idol. And they’re very competitive with each other because of it,” the source said.

The source also claimed that Underwood became even more upset with Clarkson when she dropped her Kellyoke album on June 9. After all, it coincided with Underwood’s Denim & Rhinestones release.

“Carrie worked long and hard on her album. She co-wrote most of the songs and the lyrics came from her heart. Then there’s Kelly, putting out an EP of the cover made famous by other people. Kelly’s album was meant to be a fun record to listen to on summer road trips, but you can’t step on Carrie’s toes like that and not feel the consequences from Carrie and her fans,” the source said.

Clarkson doesn’t allegedly see what the big deal is. After all, she knows that she has a strong fan base and so does Underwood. However, it’s obviously a big deal for Underwood.

To make things worse, the two singers’ personalities never allegedly jived with each other.

“Their personalities never meshed and that’s why they keep annoying each other. Carrie is methodical, focused, and plans things years in advance, while Kelly is much more of a seat-of-her-pants follow her-gut kind of girl. Kelly wanted to show everyone they could be friends, and it seemed like Carrie turned up her nose at the offer. Kelly’s never forgotten it. She thinks Carrie’s a stuck up,” the source said.

As of late, Underwood and Clarkson have never opened up about their alleged feud. And if there’s really a tension between them, this would’ve already been reported by the press no matter how hard they try to keep it a secret.