Fallon and Timberlake have been long-time best friends, sharing many iconic moments on "The Tonight Show," as well as Timberlake's various appearances on "SNL" when Fallon was a cast-member. Biel, on the other hand, is his wife. So does a guy's best friend know him better, or his wife?
It turns out the answer is more complicated, and a little uncomfortable, as Timberlake made them face tough questions like naming his favorite drink, rapper and even identifying his safeword.
It was pretty clear throughout that the three of them have a great relationship, and we couldn't help but laugh along as both of them guessed his safeword, though neither of them was particularly confident about the answer they gave.
One of the things that made it so funny was that Timerblake remained silent throughout the bit, only using cue cards to identify his questions and answers, as he is currently on vocal rest. But that didn't stop him from gesturing and mouthing words here and there, like when he gave his wife a hilariously silent "Damn!" after a particularly scathing burn she shot at Fallon.
It all came down to trying to identify what number Timberlake was thinking of. Find out who won the game, and who stormed off the set in anger, in the video above.
And then tell us why Timberlake can't be Fallon's announcer and/or sidekick on the show. We know he's busy, but so is Fred Armisen and he's still technically Seth Meyers' bandleader. These two are so funny together, we're just saying we want more. And more. And more. Is that too much to ask?
In this case, though, it was Biel who got in the final word, as she said farewell to Fallon with her fist. You can check out that memorable exchange below.