Avengers: Endgame is out this week, and most - if not all - of the talk on Reddit and Twitter has been powered by theory and counter-theory as to what's going to happen. One idea has reigned supreme, though: the Thanos bum theory.

Josh Brolin, who plays Thanos himself, isn't really sold on it.

"I don't know what that whole thing was about," Brolin told Variety at the Avengers: Endgame premiere last night, looking suddenly quite concerned about the prospect of being exploded from the inside out by Paul Rudd. "I really don't."

If you're unfamiliar with the theory, strap in. Ant-Man can, of course, shrink down to the size of an ant. So, fans reasoned, why not exploit Ant-Man's ability to change size in the fight to save the universe? Why not get Ant-Man to shrink himself down, crawl into the murderous finger-clicker's bum and, beyond that, up into his colon, then expand to extreme height and burst Thanos apart in the process?

There are some problems with that - chiefly, that it's a bit Eurotrip, and bums are never ever mentioned in the Marvel Cinematic Universe - but it could work. First things first, though: does Thanos have an anus and rectal canal at all?

"Does Thanos have a butt?" Brolin mused. "Did you see what I posted today? That’s a peach, man, that’s a peach. That’s a purple peach if I’ve ever seen one, that’s a beautiful, purple peach."

Brolin was referring to this Instagram post from yesterday, which will presumably be rugby-tackled into the NSFW dustbin by overzealous moderators in the near future.

instagramView full post on Instagram

Certainly, that's not something you'd want any younger relatives to be exposed to without some context, even if that context is: "This actor is sharing a picture of a gargantuan CGI bum because some grown adults with jobs and mortgages enjoy pretending that the biggest film franchise in history will end with Paul Rudd - that nice man from The Cider House Rules - crawling up his anus before bursting him like a ripe purple watermelon."