The pop star stopped by "The Tonight Show Starring Jimmy Fallon" Thursday night, but due to bruised vocal chords, he was left using only pen and paper and charades-like hand gestures to tell his pal all about Halloween with Jessica Biel and the kids, and his new book, "Hindsight: And All the Things I Can't See in Front of Me."
So how exactly did JT bruise his vocal chords? He mouthed to Fallon that he was running up a mountain, got attacked by a bear and screamed for dear life.
Timberlake, of course, was only joking. He clarified the real reason he couldn't speak was because he was swimming in the ocean and got attacked by a shark -- again, screaming for dear life. We'd like to believe one of those two stories is true.
JT mouthed that his wife "loves" his inability to speak, and Fallon joked back, "This is probably the best thing to ever happen to Jessica!"
The two then flipped through some pages of Timberlake's memoir, and Fallon was quite pleased to find himself splattered across a few sections.
But Fallon was determined to conduct some kind of interview, so he pre-recorded what he thought his friend would say, handed him a phone with a display of a similar-looking mouth, forced him to hold it up to his face and went to town.
"We agreed you shouldn't sing at all, but could you just give us a little bit of a favorite song?" Fallon asked. "Can you do 'Mirrors'? C'mon, please? I just think everyone would love it so much."
At the end of the awful rendition, JT mouthed, "You motherf--ker." There's nothing else we can say about the performance except that you must watch it to appreciate it in all its glory.
The two goofballs then took turns turning their heads and looking directly into the camera to give the tiniest head nod they possibly could -- without laughing.
They were supposed to complete the task "while maintaining the utmost composure." Naturally, the opposite occurred.