Ashlee Simpson-Wentz called her husband "horrible" during a drunken public argument.
The 'Outta My Head' star is said to have rowed with Fall Out Boy rocker Pete Wentz during his DJ set at his Chicago bar Angels and Kings at a party to mark the venue being open for a year on Saturday (15.08.09).
After aiming a series of series of barbed comments at Pete, Ashlee insisted he took her home early.
A source told gossip blogger Perez Hilton: "Pete was in the DJ booth when Ashlee came up completely wasted and yelled at him to leave. They fought, she told him he was horrible in front of a whole group of people and made him leave his own party early. So they make a scene and leave the bar."
Sources say Ashlee was "beyond drunk" and the pair continued to argue as they left.
When someone tried to take a photo of the couple, Ashlee "chased the guy down the street and made him erase the pictures".
The couple - who have a 10-month-old son Bronx - were then ushered into a car by their security team and taken home.
Ashlee, 24, has since denied she and 30-year-old Pete rowed at the bar.
Writing on her Twitter page she tells Perez: "Your story is WAY off. my husband is an amazing dj and was dedicating songs to me. We were just havin fun. Our love is amazing. (sic)"
Perez insisted the story was accurate, posting on his own micro blog: "I don't want to name names and get people fired but several of the people I spoke with work at Angels and Kings. I'm not wrong."
This is not the first time Ashlee has been caught up in a drunken altercation.
In June, the singer had a public row with Pete's ex-girlfriend Michelle Trachtenberg during a night out in Los Angeles.
A source said at the time: "Ashlee was staring directly at Michelle and starting hurling insults at her. She was grinding up on Pete like a stripper. It was actually pretty disgusting!"
Ashlee later apologised for her behaviour.