Gossip Girl herself would be proud of how many secrets the cast of the O.G. Gossip Girl have been spilling on the Xoxo podcast.  Hosted by Jessica Szohr, who played Vanessa in the oh-so-dramatic series, the podcast has been revealing all the behind-the-scenes details of the CW show, which ran from 2007 to 2012, but will always have a special place in our hearts.  The latest bombshell? Aside from the casting director David Rapaport sharing that Jennifer Lawrence almost played the part of Serena van der Woodsen (which ultimately went to Blake Lively), Ed Westwick also dished on his on-screen "chemistry" with co-star Leighton Meester, who played Blair Waldorf opposite his...