So bromantic! Ben Affleck celebrated National Best Friends Day, Wednesday, June 8, by sharing the most adorable throwback Instagram of longtime BFF Matt Damon and himself.

“This guy,” the Argo actor, 43, captioned a collage featuring four photos of the pals goofing off at a birthday party for Damon, now 45. “#NationalBestFriendsDay.”

This guy. #NationalBestFriendsDay

A photo posted by Ben Affleck (@benaffleck) on

Their friendship was recently honored at the taping of Spike’s Guys Choice Awards 2016 on Saturday, June 4. The duo, who have partnered on many projects in the past and have won multiple awards together, were presented with the Guys of the Decade award, an accolade that both actors were stoked to receive.

"I think it goes without saying that this is an award Matt and I have been dreaming about since we were little boys," Affleck told the crowd during their acceptance speech. "I did Gigli, and Matt did that Liberace movie and all of a sudden, it all seemed out of reach. Then I did [Batman v. Superman] and all of a sudden, it was back in reach again."

Damon also expressed his gratitude. "We will cherish this, and we want to recognize some of the other nominees,” he added before jokingly taking aim at another noteworthy bromance of the late ‘90s and early aughts: "Some of the dudes who weren't quite as decade-worthy: George Clooney and Brad Pitt."

The guys grew up together in suburban Massachusetts. Naturally, they bonded over their Hollywood aspirations and, eventually, both moved to L.A. to pursue acting and filmmaking as a team. In 1997, Affleck and Damon hit it big with the release of Good Will Hunting, which both men starred in and wrote. The film won two Academy Awards in 1998.

Since then, they have remained best buds and have seen each other through both the good times and the bad. Damon, who shares four daughters with wife Luciana Barroso, has been there for Affleck after Jennifer Garner filed for divorce from the Gone Girl star last summer.

In August 2015, Damon told Entertainment Tonight that Affleck was doing all right following his split from the Mother’s Day actress, 44. "He's good," Damon said at the time. "He's good.”

Us Weekly broke the news last July that Affleck had been dating the couple’s former nanny, Christine Ouzounian. After the report came out, a source close to Garner, with whom Affleck shares three children, told Us that the actress was “disgusted."

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