01/06/2009 05:12 am ET Updated May 25, 2011

Mary-Kate, Kirsten Dunst, Tom Brady And More Flock To Art Basel Parties

THE Art Basel convention in Miami has always been more about the parties than the art, but some revelers seem to be taking the concept to a whole new level.

Pint-sized Mary-Kate Olsen has cut a particularly wide swath through the town. On Wednesday night, Olsen and Kirsten Dunst got into a heated argument while sitting together at Audi's party at the Delano in South Beach. "They just kind of stared at each other for a long time and then started exchanging nasty words," says an onlooker. "Then Olsen just got up and left. She's been going really late every night." Olsen and her boyfriend, artist Nate Lowman, were also out until dawn with DJ Paul Sevigny at club Bella Rose the night before.

Says another partygoer at the Delano: "She 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."

Earlier that night, Dunst, a staple of the downtown party circuit who did a stint in rehab for depression this year, tried flirting with newly crutch-less (and Gisele Bundchen-less) Patriots quarterback Tom Brady, to no avail. She later left the bar with Brady's manager, Will McDonald.

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