LOS ANGELES, Oct 30 ― Jimmy Fallon’s Tonight Show is always pretty hilarious, but this particular episode garnered two million views within just a day of being uploaded online.

Both Jimmy and his guest, the ever popular Justin Timberlake, have loads of fun guessing each other’s answers in the game ‘Best Friends Box’, and throw in a song too just for the heck of it.

So, how well do these buddies know each other? You have to check out the video to find out.