Watch out Penn and Blake. Looks like there might be another on-set couple aiming to steal your thunder.

According to spies for both the New York Post and W Magazine, Gossip Girl co-stars Jessica Szohr (Vanessa) and Ed Westwick (Chuck) got quite cozy this holiday weekend. The two, along with Chace Crawford (Nate), were all stuck in the Dallas/Fort Worth airport on Sunday on their way back to New York. (The trio may have been visiting Crawford’s family in the Plano area.) It’s in that oh-so-romantic terminal where kisses were witnessed.

“They were trying to be discreet by stealing kisses near the gate,” one tipster reported. Another spy said their flirtation was not something that could be mistaken. “Not a French kiss, but a smooch definitely. They were being very flirty when people were not paying attention.”

So were Jessica and Ed still drunk on spiked eggnog…or are they really pursuing off-screen what Chuck and Vanessa came very close to doing on? Sounds like we need to get GG on the case!