Also in attendance at the party were the children of Garner and Affleck's celebrity pals, including Reese Witherspoon's son, Tennessee, who dressed as Captain America!
The previous night, Affleck was at a party of a different kind. He was spotted leaving the William Morris Endeavor pre-Oscar party at a Beverly Hills mansion, looking very dapper in a three-piece suit.
When Garner spoke about her and Affleck's divorce to the magazine, she revealed that the separation occurred months before the Batman v Superman star's alleged affair with former nanny Christine Ouzounian. "She was not a part of the equation," the 43-year-old actress said.
The Dallas Buyers Club actress also spoke about her motivation for remaining on good terms with Affleck. "The main thing is these kids -- and we're completely in line with what we hope for them," she said.
"Sure, I lost a dream of dancing with my husband at my daughter's wedding. But you should see their faces when he walks through the door. And if you see your kids love someone so purely and wholly, then you're going to be friends with that person."
So far, Affleck has not commented publicly on the article.