Carrie Underwood has reportedly branded Jessica Simpson fat in a jealous spat over Tony Romo.

The American Idol winner - who used to date the Dallas Cowboys quarterback - is said to have been less than impressed when Jess gushed about her man in a recent interview.

OK! quotes a friend of Carrie’s as saying, “She finds Jessica’s love of putting her life on display pretty desperate.

"She laughed at the People cover, because it’s the same one Jess did about John Mayer - same smile, same look, except she’s a little fatter.”

Jess had told People, “I just told him (Tony) today, ‘You’re the love of my life.’ ”

The Dukes of Hazard star also went onto to say she didn’t feel threatened by Carrie’s calls to her quarterback boyfriend.

What’s next? Hair pulling?