The fun wasn't over for the Met Gala 2013 attendees in NYC last night as they flocked to the Standard Hotel following the ball for the official afterparty at the Boom Boom Room. Madonna stripped out of her bum-baring Met Gala outfit and changed into a fishnet body stocking and black lacy lingerie to mingle with guests like Katy Perry, Allison Williams, and Frank Ocean. She wasn't the only star who made a costume change — Amanda Seyfried took off her gown and changed into a baggy black t-shirt to hit the dance floor with Frank. Meanwhile, Miranda Kerr met up with January Jones, Jennifer Lawrence arrived with Marion Cotillard, Gerard Butler mingled with Karolina Kurkova, andNicole Richie connected with Kirsten Dunst, and Mary-Kate Olsen snuggled with boyfriend Olivier Sarkozy. Mary-Kate and Olivier weren't the only couple at the late-night bash, as Jennifer Morrison was spotted holding hands with her Once Upon a Time costar Sebastian Stan and Kate Bosworth hugged Michael Polish. If you missed out on all the excitement last night, be sure to check out our collection of all the red carpet fashion from the 2013 Met Gala to get caught up!