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Justin Timberlake and Keegan-Michael Key crack up during 'Tonight Show' sketch

On The Tonight Show Starring Jimmy FallonJustin Timberlake and Jimmy Fallon found themselves in a sketch playing campers at Camp Winnipesaukee in 1993. Timberlake and Fallon were in their cabin trying to get some shuteye, but they just couldn’t help but sing “What’s Up?” by 4 Non Blondes even though it was time for lights out.

Although they tried singing the song softly at the beginning, they ended up belting out the tune and drawing the attention of camp director, Mr. Fletcher, played by Keegan-Michael Key. Key asked them to stop their “ruckus,” but despite his warning, as soon as he left, they went right back to singing.

The second time he came in, Key really laid down the law — letting his whistle dangle in Jimmy’s face, which Jimmy took the opportunity to blow. Throughout the whole sketch, Timberlake could barely keep it together, and the whistle moment put him over the edge. “You OK?” asked Key. “Yes — it’s allergies,” Timberlake replied.

The Tonight Show Starring Jimmy Fallon airs weeknights at 11:35 p.m. on NBC. Watch clips and full episodes of The Tonight Show free on Yahoo View.

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