The ring featured a diamond solitaire on a gold band and was one we've never see Katy wear before, so many fans thought the singer's beau John Mayer might have finally popped the question.
While Katy hasn't addressed the engagement rumors herself, an insider did tell Us Weekly that "it was just a ring that went with the outfit," adding that "she's not engaged."
For what it's worth, Katy did ditch the diamond later in the evening when she changed outfits, so it stands to reason that it WAS just an accessory--but surely she knew that wearing a diamond on her ring finger would get everyone talking, right?
As for now, Katy and John are still going strong, with a source telling the mag "it's just a question of when John will propose."
Since we're huge fans of Katy and John, we're hoping "when" comes sooner rather than later!