A fab face is a terrible thing to waste — unless, of course, it’s covered by a Met Gala mask. Haute headpieces were on parade Monday night for the annual event, ringing in the Costume Institute’s spring exhibition, “Costume Art,” a celebration of the dressed body and art, opening at The Metropolitan Museum of Art, May 10. Nailing the night’s dress code , “Fashion Is Art,” en vogue icons stomped the museum’s swanky staircase in dazzling disguises from top fashion houses. Perry struck a chord on social media after donning her mask at the 2026 Met Gala. WireImage Katy Perry kicked off the kookiness in a futuristic, chrome face-covering to accompany a white strapless Stella McCartney dress.…