Ben Affleck Celebrates National Best Friends Day With Adorable Pics of Matt Damon

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Ben Affleck celebrated his beloved bromance with Matt Damon on National Best Friends Day with some pretty epic flashback pics.

On Wednesday, the 43-year-old actor posted a photo collage from one of Damon's birthday celebrations that showed Affleck wearing a cake on his face. "This guy," Affleck captioned the sweet Instagram post.

The Batman v Superman star's tribute to his pal comes just a few days after the Good Will Hunting stars accepted the Guys of the Decade award at the 10th Spike TV Guy's Choice Awards in Culver City, California on Sunday night. "I think it goes without saying that this is an award Matt and I have been dreaming about since we were little boys," Affleck joked. "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."

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"Now we're the…coveted Dudes of the Decade...the Guys of the D**kheads?" the father-of-three further quipped.

"No, the D**kheads of the Decade Award. What is it called?" Damon, 45, added before getting it right. "It's the Guys of the Decade."

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The actors concluded their time on the stage with a heartfelt thank you to the troops, who they also made time for during the event. An eyewitness tells ET that the actors were surrounded by service men and women throughout the night. Damon and Affleck sat by the troops during the show and were seen taking pictures and selfies during a commercial break.

Affleck is such a good friend that he snuck Damon onto the Jimmy Kimmel Live! set after the Oscars in February. Check out the hilarious moment:

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