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 throughout the week's preparations for the show. "I must be more of a role model than I thought," she deadpanned before acknowledging that the fan base had actually gathered for Bieber.

"He was one of the babies in 'Baby Mama' -- two years ago," she joked about her past association with the singer.

Bieber then joined Fey on stage for a brief rendition of "I'm Every Woman" (a hit for both Chaka Khan and Whitney Houston), which was used to comically demonstrate how Fey juggles her responsibilities on "30 Rock," "Date Night" and other creative endeavors, including her guest stint on "SNL."

Later, Bieber starred in a skit as Jason Deeps, a C+ student in Tina Fey's fictional high-school science class. Fey's teacher character constantly fantasized about Bieber's character, a student she described as "a dreamy Christmas elf" who looked like "a baby bunny sniffing a tiny flower." In response, Bieber's Deeps flirted with Fey -- presumably setting young hearts aflutter across the country -- and sang her a variety of fantasy songs, during which he promised to "buy her a Panini and some spanks to make her teeny."

Immediately thereafter, Bieber hit the stage for an energetic performance of "Baby," the hit single from his My World 2.0. LP. Accompanied by a group of dancers, Bieber did a solid job on the song's rap section, performed by Ludacris on the record.

For his second performance, Bieber sang "U Smile." At the end of the song, Bieber told Fey that every time she smiles, he smiles.

In addition to Bieber's contributions, the "Saturday Night Live" gang lampooned several hot topics including Jesse James' alleged infidelity towards Sandra Bullock, Tiger Woods' recent return to golf and President Barack Obama's 2010 Census Form.

Fey also reprised her famous impersonation of Sarah Palin, pretending to launch an Oprah Winfrey-inspired television network with programs such as "Are You Smarter Than a Half-Term Governor," "That's So Palin" and "The Tonight Show With Jay Leno."

The Fey-Bieber lovefest concluded with a big hug during the show's finale.

What did you think of Justin Bieber's appearances on "Saturday Night Live"? Let us know in the comments below!