The only thing these two country singers have in common is Tony Romo - Carrie used to be his girlfriend before Jessica. Jessica denied rumors that Tony still talks to Carrie after she checked his call log. Since then, the trash-talks between these two ladies have become endless.

A source close to Underwood tells OK! Magazine that Romo and his ex-girlfriend Romo are still friends and talk, saying, "She's livid that Jessica would feel the need to publicly try and embarrass her when it's Jessica who should be embarrassed. Her boyfriend is calling Carrie behind her back!"
Carrie Underwood and Jessica Simpson heat up the fight just to prove whether Tony is still keeping in touch with his ex.
OK! Magazine reported in May that Tony still calls Carrie up. A source even told the mag, "They talk and text regularly. They broke up as friends, so there's no reason for them not to talk."
Meanwhile, in a radio interview with Jessica Simpson on a Nashville radio station, she talks back saying, "I looked at his call log. Tony and I both laughed. We got a chuckle out of it," describing how they react regarding Carrie's assertions that she still talks to Romo.
A friend of Carrie responds to Jessica's radio interview and tells OK! magazine, "She's (Carrie's) livid that Jessica would feel the need to publicly try and embarrass her when it's Jessica who should be embarrassed. Her boyfriend is calling Carrie behind her back!"
The two blond singers would be attending the CMA Awards scheduled on the 12th of November to promote their respective albums.