"What's up, Facebook?" Damon says in a video posted on Affleck's timeline. "Ben went to the bathroom -- we're in the office -- so I'm taking over his Facebook page for a minute. I think you may have heard Ben claims to be friends with Tom Brady. May or may not be true."
Just minutes earlier, Damon changed Affleck's profile picture, Photoshopping his own face over Affleck's in a photo of The Accountant star with the Super Bowl champ. To drive the point home, Damon scribbled the letters "BFFs" on the altered pic for good measure.
This comes after Damon and Affleck posted a video to Brady's Facebook last month in which they pretended to argue about who was closer to the NFL pro. In the video, Affleck even compared his looks to Brady, claiming they have similar chins.
"Let me tell you something, if your chin was anything like Tom's, that Batman movie of yours would have made about $4 billion," Damon argued. "Because that's the only part of you that's recognizable, is that big, ugly chin. Tommy's a superhero."
The whole back-and-forth is all in jest, of course. The actors are trading blows as a marketing shtick to promote an Omaze campaign, which will benefit various philanthropic efforts, that encourages fans to donate $10 for a chance to, if chosen, hang out with the Oscar winners and the New England Patriots quarterback.
In reality, Brady is good friends with both men. Last year, he credited them with helping him get through the highs and lows of his career.
"[Those] guys in particular, I've gotten to know over the years and they're all friends," Brady told ET. "They believe in what we're doing, and it's great to have such great support from, you know, all those guys."