Watch Fallon, the Roots and Lonely Island perform 'YOLO'

Jimmy Fallon might be a brand new dad, but that doesn't mean he's given up on the fun.

Thursday on "Late Night," the host teamed up with his house band the Roots and Andy Samberg's hip-hop comedy trio the Lonely Island for a surprise performance of "YOLO."

The song is an ironically titled ode to playing it safe -- by cooking meat thoroughly, avoiding lice-ridden children and always wearing (and double-locking) your chastity belt.

Because, after all, you only live once. Why not be careful?