Halloween was full of surprises, but none as shocking as Leighton Meester joining Weezer on stage at their Halloween show in NYC! We were there and when Leighton took the stage in her tie-dye, we could not have been more psyched. She sang Weezer's new song "(If You're Wondering If I Want You To) I Want You To" and it was awesome! Who else surprised us on stage? One of the bros from the Naked Brothers Band! Check back for our exclusive interview and performance with Weezer!