Justin Timberlake is one of the hosts at tonight's Costume Institute Gala along with Marc Jacobs and Kate Moss. The budding fashion designer had a very va-va-voomed up Jessica Biel on his arm as he walked the red carpet. JT's quite the fashion plate, but he decided to play it safe and distinguished while she looked sun-kissed after her big weekend run. This is just the beginning of a big week hosting in NYC — Justin is doing SNL this Saturday night too. Check out all of Fab and Bella's live love it or hate it polls here!