LOL Alert! Matt Damon Pops Out of Ben Affleck's Coat, Crashes Jimmy Kimmel's Post-Oscars Special

You have to see this to believe it.

Days after Jennifer Garner opened up for the first time about her split from Ben Affleck, the Batman v Superman star dropped by Jimmy Kimmel's post-Oscar special in what appeared to be a fat suit.

"Wow, you look healthy," Kimmel said sarcastically when Affleck, wearing a dramatically oversized trenchcoat, sat down for his chat.

"You do the superhero movie and you get muscle and then muscle turns to fat. An off-cycle," Affleck explained.

RELATED: Ben Affleck Joins Jennifer Garner for Son Samuel's Birthday Party

"No offense. I really don't mean to put you in an uncomfortable situation but you look -- you've really ballooned up," Kimmel said in response.

"Thanks, I didn't think this was about body-shaming tonight," the 43-year-old actor said.

Movement in the "fatsuit" tipped the late-night host off that there was something more going on. Sure enough, it wasn't a fat suit at all but Affleck's BFF Matt Damon, aka Kimmel's archnemesis! Just priceless.

RELATED: Jennifer Garner Breaks Silence About Ben Affleck Split and the Nanny Scandal

"I just think it's gone on long enough," Affleck said of Kimmel and Damon's beef. "I think it's maybe time to bury the hatchet, man!"

"You get to decide when it's time to bury the hatchet?! Do you know what he's done to me?" Kimmel tried to reason, while Damon -- poor guy -- remained kneeling on the floor until Affleck invites him to sit on the couch.

"Wow!" Damon exclaims, as if his life has turned a page: "This feels amazing!"

"You're ruining the Oscar show, nobody wants you here," Kimmel berates The Martian star. Too bad his own audience doesn't feel the same way!

RELATED: Jennifer Garner Has the Most Epic Response to Ben Affleck's Giant Back Tattoo: 'Bless His Heart'

"I still feel like Dorothy!" an ecstatic Damon says, before Kimmel has the cameraman cut the Oscar-nominated actor out of frame and physically removes him offstage.

After Kimmel showed a photo of the two at the 1998 Academy Awards, the first time they won their Oscar for Good Will Hunting, Affleck made a joke at Damon's expense.

"I've been figuratively carrying him for years! Literally," he jokes.

Earlier in the episode, Damon stealthily trolled an interview Kimmel's sidekick Guillermo was conducting with Sacha Baron Cohen and even popped up in a hilarious Batman v Superman/The Martian spoof.

Never end this feud!