"They were hanging out at the after-party at Refinery Rooftop till closing time. They looked cosy in a corner," a source told the New York Post newspaper.
Despite their apparent closeness, a friend of the actress insists that Seyfried and Long are just friends at the moment.
Seyfried has previously dated actors Ryan Phillippe and Dominic Cooper, while Long was in a long-term relationship with actress Drew Barrymore that ended in 2010.
