What is the mark of a true best friend?
Is it staying by someones side and supporting them through thick and thin?
Or is it demonstrating weird knowledge of each other to a national TV audience?
Credit: NBC
The game involved the participants trying to guess the other guys answer to a question.
Unfortunately for them, Ruffalo and Fallon dont actually know that much about each other.
For instance, whats Ruffalos favorite sandwich?
(This is essential best friend knowledge).
Fallon guessed BLT, but the real answer was peanut butter and jelly, almost the complete opposite.
Fallon thinks Ruffalos greatest fear is being alone in the world, but its actually drowning in milk.
Thankfully, the final question was for Fallons favorite superhero.
Watch the full clip below.
