Troian Bellisario, Lucy Hale (in Rebecca Minkoff) and Shay Mitchell, the stars of ABC Family’s Pretty Little Liars, teamed up on ‘A Day’ at the 2012 ABC Family Upfront presentation held at the Mandarin Oriental Hotel in New York City. During last night’s episode, the show revealed its notorious mystery character, A. “#PrettyLittleLiars has the BEST fans ever. EVER. So proud to be a part of this amazing family,” Tweeted Mitchell after the game-changing episode. Click through the gallery to see more stars at last night’s hottest events.