Last night we braved the humidity and crowds at the Met Gala red carpet to stalk the celebrity arrivals. Though we didn't get Lady Gaga, who didn't walk the carpet, we did chat to Katy Perry about her light-up dress. "The trigger button is in my breasts," she explained of the lighting mechanism. "Which is great for the evening because when Anna walks over and says, 'Turn that crap off,' I’m like, ’Okay, it’s off.’" Janet Jackson and Hugh Jackman said they were toasty but enjoying the humidity. "I’m not hot," countered Gisele. "Believe me, I’m Brazilian and it's 100 degrees in Brazil all the time.” See more in the video.