Bradley Cooper (left) and Josh Brolin
03/10/2013 at 12:00 PM EDT
Josh Brolin – who recently split from Diane Lane
after eight years of marriage – stepped out on Friday night with friends Bradley Cooper
, Benicio Del Toro and Michael Fassbender
They stopped by Skybar at the Mondrian Los Angeles, where Fassbender ordered a round of beverages for the group, an onlooker tells PEOPLE.
Laughing as the night went on, the crew of actors stayed well past closing, the source adds.
"They were in good spirits having fun!" the source says. "It looked like a very relaxed night out."
The guys' night out comes after James Brolin told PEOPLE
that Josh and Lane's split was "mutual" and that "it's all okay."
– Jennifer Garcia