Justin Bieber and Tina Fey Make A Dynamic Duo On SNL

Justin Bieber was this week's musical guest on "Saturday Night Live," but the teen sensation's appearance went far beyond that. In fact, Bieber practically acted as a co-host for Tina Fey by energetically participating in several of the show's skits.

Bieber made his debut during Fey's opening monologue. The "30 Rock" star joked that she'd noticed an unusual amount of young female fans