The heat in Brazil must have had our girl feeling a little frisky while promoting her movie Part of Me, because she stepped out in a daring canary dress with intricate laser cutouts on the chest, and skipped the bra all together.
Of course, the beauty looked flawless in the form-fitting dress, but it was a bold selection for the normally playful Katy.
The 27-year-old pop phenom also opted out of her normally technicolor hair for a demure jet black bob cut.
The movie wasn't the only thing in 3D! Check out the gallery above to see Katy working the heck out of this yellow dress.