Back in June 2010, she flipped the bird during a Mets-Padres game at Citi Field in New York... which got her into a war of words with Mets superfan Jerry Seinfeld.
Seinfeld called Gaga a "jerk" -- but maybe he was just annoyed to learn that she pulled the stunt while sitting in his private box.
Her baseball escapades didn't end at Citi Field.
Click "Next" for her even more outrageous followup act at Yankee Stadium.
