"Audrina hates Kristin, and MTV sprung this on her last minute so she decided to cancel," a source dished to In Touch Weekly. "She doesn't even want to be in the same room with Kristin."
Patridge's stylist and hair and makeup team have been warned by Audrina not to book a job with another celeb for the VMAs or else.
Of course, Kristin is more than pleased by the news of Audrina's last-minute cancellation.
Says a friend of Cavallari's: "Kristin is happy she won't be with Audrina. They never got along and Kristin is the star of The Hills, not Audrina."
Do you think it was Audrina's decision, or did MTV play a heavy hand in Patridge pulling out?