Justin Timberlake and Jimmy Fallon Sing at Camp With Billy Crystal and Keegan-Michael Key

Camp Winnipesaukee Still — H 2017
Courtesy of 'Tonight Show'

The campers sing "What's Up" and "Rhythm Is Gonna Get You" as their counselor (Key) scolds them.

Jimmy Fallon brought Justin Timberlake, Keegan-Michael Key and Billy Crystal to Camp Winnipesaukee on Tuesday's Tonight Show for some mischievous singing.

The skit starts with Fallon and Timberlake as camp attendees who struggle to keep it down after lights out. They sing into their flashlight-microphones, starting with "What's Up" by 4 Non Blondes. 

In the midst of the singing, camp counselor Key comes in and tells them he needs them to "stop the ruckus" or they will miss out on every kind of soup at the Snack Shack the next day. When they misbehave again, he comes in to scold them and Timberlake and Fallon have a hard time not breaking into laughter as they continue the sketch.

Crystal sneaks in from Camp Buttonwood and the three boys break out their rendition of Gloria Estefan's "Rhythm Is Gonna Get You." 

Billy Crystal also sat down with Fallon for an interview and spoke about his "Spend the Night With Billy Crystal" tour. He remembers a small part of the tour in which he make a joke about Trump's unpredictability and low approval ratings.

A woman took issue with Crystal's joke and started heckling him, telling him to "honor the president." After she repeated it a few times Crystal stopped explaining to her that it was just humor, and told her he was going to use Trump's words against her.

"I'm going to use your own president's words on you if you love him so much, 'Get her out,'" said Crystal. He said after the show, her husband — who had stayed after his wife left — came up to him and said he was a big fan.