We have four words for you: "Gossip Girl"-"O.C." crossover. This East Coast-meets-West Coast couple is a match made in CW television heaven, and we're making high-pitched "Aww!" noises just like the network's target audience. Leighton and Adam connected while working together on the film "The Oranges" and have been quietly seeing each other ever since. Blair and Seth! Who would've thought?