Justin Timberlake & Jimmy Fallon Return to Camp Winnipesaukee With Two Guest Stars - See the Hilarious Sketch!

NBC "Late Night with Jimmy Fallon"

Justin Timberlake and Jimmy Fallon have returned to Camp Winnipesaukee!

During Tuesday's episode of The Tonight Show Starring Jimmy Fallon, the two reprised their roles as two '90s teens at camp (curly wigs and all!) that refuse to go to bed after lights out.

WATCH: Jimmy Fallon and Justin Timberlake Poke Fun at Their Epic Friendship

This time, they were joined by two special guests -- Keegan-Michael Key as a counselor and Billy Crystal as a fellow camper.

The clip begins with Timberlake telling Fallon he's wide awake as a result of eating "like, seven Charleston Chews." The two then play a game of Two Truths and a Lie, later bonding over their mutual love of "What's Up" by 4 Non Blondes… and waking up the other campers.

That's when they receive a visit from Key, shortly before Crystal stops by.

"You were just singing a song?" Key asks. "Is that what you were doing? Because it sounded like you were just drowning in a lake."

See what happens next by watching the full 10-minute segment below:

WATCH: Justin Timberlake & Jimmy Fallon Test Their Friendship, Sing 'Ironic' and Throw Pizza Party on 'Tonight Show'

During their Camp Winnipesaukee sketch last October, Fallon and Timberlake threw a pizza party and took on Alanis Morissette's "Ironic."

See highlights from that skit in the video below.