It was sort of obvious. Well. To me. I have a grand total of six siblings, so I'm thoroughly qualified to judge. I guess other people could miss it.
But honestly, if they wanted to hide the fact that they're brothers, they could at least try to hide the obligatory sibling bickering. When they turn on the snark, I swear the temperature of the room rises twenty degrees. They're really, really good at it.
Then again, they clearly enjoy it. And can I really fault them for wanting to bond?
No, I guess not.
(Though they're still sort of obvious).