Are Leighton Meester & Justin Long A Couple?

New couple alert? A single Leighton Meester and Justin Long were spotted holding hands outside La Poubelle in Hollywood while they ate dinner on Sunday. 

"They were happily willing to talk to fans who approached them," an onlooker says of the duo, who dined for two hours. They stayed at the restaurant past midnight. 

Reps for the actors didn't immediately comment about their relationship.

Credit: PEOPLE