Mary-Kate Olsen and Kirsten Dunst Fight in Miami

Mary-Kate Olsen is still in Miami enjoying Art Basel but her fun was dampered a bit when she got into a public argument with Kirsten Dunst on Wednesday night. The pair were sat together at a table at the Audi party and, at first, seemed to get along. But then the conversation turned sour. None of the onlookers who spoke to the tabloids seemed to know what the argument was about.

“They just kind of stared at each other for a long time and then started exchanging nasty words,” a source told Page Six. “Then Olsen just got up and left.”

However, another source speculated perhaps it wasn’t Kirsten who set MK off, rather, she was just the victim. MK “looked like she had not brushed her hair in a week and she was chain-smoking the entire time and sitting like a sourpuss with her boyfriend. She was acting very oddly.”

Its possible that MK just isn’t having a great time. I’m sure Nate is super-busy and finding out the paparazzi has followed you to Miami can’t be great. Any other ideas as to why MK would be having a not-so-fun time and get into a random fight with Kirsten?