Matt Damon got back at Ben Affleck and Jimmy Kimmel for heckling him about not having Twitter by sending them a funny fax Credit: Courtesy Jimmy Kimmel; Ray Tamarra/WireImage

That'll teach 'em! Matt Damon seems to have gotten back at Ben Affleck and Jimmy Kimmel for teasing him about his nonexistent Twitter account by sending them a faxed shot of his bare butt.

"Dear Ben & Jimmy," the accompanying note read. "Here's my fax. Love, MD. Faxtag: KimmelHasManBoobs."

Kimmel shared the funny memo via Twitter, writing, "@BenAffleck -- did you see what your 'friend' Matt faxed to us? NSFW." Affleck, in turn, replied, "Looks like u from here, Jimmy. All 4 charity?"

The trio's online joke war started last week, when Affleck took to Twitter to promote a charity contest benefiting Eastern Congo Initiative and The contest gives two lucky fans a chance to hang out with the Argo director and BFF Damon in Hollywood.

"@JimmyKimmel -- I thank you buddy," Affleck tweeted after Kimmel voiced his support for the charity effort. "And @easterncongo & @water thank you! Matt, on the other hand? Matt, you there? Right. We will fax you."

Kimmel, 46, then added his own jab at the Twitterless Damon. "Matt is probably too scared to get on Twitter because no one likes him," he joked.

Added Twitter CEO Dick Costolo: "@BenAffleck, @JimmyKimmel, @water, we have printed out this tweet and placed it in a suitcase that we will have couriered over to Matt."