Rumors were swirling after Mischa Barton showed up an hour and a half late to her 21st-birthday dinner at Graydon Carter’s Waverly Inn on Thursday night. Barton’s table sat at 9 p.m., but the b-day girl, in a flowing white dress, didn’t show until 10:30. Her guests were not angered but saddened to learn that the delay had been caused by the death of the starlet’s family dog, Bean. Still up for celebrating, though, Barton ended the night with a bash at the Gramercy Park Hotel’s Rose Bar.