Yesterday Jimmy Fallon and Justin Timberlake Did the ‘Single Ladies’ Dance and ‘History of Rap 6’

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Unfortunately not captured below: the moment immediately after this, when Justin leaned over to Jimmy and channeled his greatest Alan, whispering, "And we're the two best friends that anybody could have. We're the two best friends that anyone could have. We're the two best friends that anyone could have. And we'll never, ever, ever, ever, ever leave each other."

Such best friends that they also did "History of Rap 6" on The Tonight Show last night: