Good Charlotte's Joel Madden has allegedly gotten into the middle of the beef between Lindsay Lohan and Hilary Duff.

Backstage at last Friday's Z-100 Jingle Ball radio festival in New York, the pop-punk singer refused to give Lohan's 8-year-old brother an autograph until she publicly apologized to Duff for their ongoing war of words, according to an eyewitness.

Lohan's brother Cody and his friend approached Madden, who had performed that evening with Good Charlotte, and asked for an autograph, the witness said. When Duff, who has been romantically linked to Madden, told him who the kids were, Madden told Cody to get his mother. Madden then allegedly demanded to an outraged Dina Lohan that her daughter apologize for her actions.

This brought Cody to tears, the eyewitness said. But he soon dried his eyes and fired off a jab of his own by asking where the guys from Simple Plan were because, he reportedly said, they were probably nicer. Screams of "Simple Plan! Simple Plan!" then filled the backstage hallways of Madison Square Garden as the boys ran away.

Simple Plan, however, were not on the bill.

Duff performed a short set during the festival, and Lohan was on hand to introduce Destiny's Child.

Lohan's publicist declined to comment on the incident, while a Good Charlotte spokesperson said she was unaware of the incident. Duff's publicist had not returned calls by press time.

The teen pop stars' feud allegedly began when both dated singer Aaron Carter last year.

For Hilary Duff's take on the beef, check out [article id="1493724"]"Hilary Duff: The Nicest Brat."[/article]