During the festivities, the 29-year-old was standing on a float shaped like a giant, glittery, high-heeled shoe while appearing before the crowd as an honorary member of the Krewe.

And, according to the society's Facebook page, that's when the singer lost her beautiful bling. They've narrowed the search to specific streets, and are even offering a reward for the missing jewelry! Ch-ch-check out their post (below)!

Zayn previewed the duet by posting a black and white pic of himself with Swifty on his Instagram -- but hey, she is bestiez with his girlfriend Gigi Hadid, so it wouldn't be unusual that they hang out... But collab?!