She’s madame X-tra. Lauren Sánchez hit the Met Gala 2026 red carpet in a custom Schiaparelli gown with a corset-inspired lace-up back inspired by John Singer Sargent’s iconic portrait “Madame X.” The painting — which was once called the “world’s most scandalous” — has long been one of the Metropolitan Museum of Art’s biggest draws. Sánchez’s navy ode had a va-va-voom low-cut neckline and pearl- and crystal-adorned straps. The Blue Origin space traveler, 56, wore her long brown hair parted to the side, showing off a dazzling pair of 60-carat diamond and pearl drop earrings by Lorraine Schwartz. She added a 35-carat single-stone marquise golconda diamond ring by Schwartz on her left ring finger in place of her huge (though not quite 35-carat huge) engagement ring . Lauren Sánchez arrived at the 2026 Met Gala in a custom Schiaparelli gown inspired by “Madame X.” WireImage A corset-style lace-up back added drama to Sánchez’s red carpet look for the “Costume Art”-themed evening.…