Justin Bieber will pull double duty on SNL as host and musical guest.

Justin Bieber will pull double duty on SNL as host and musical guest.

Justin Bieber and Jason Sudeikis get a little riff going on Bieber fever in a new promo for Justin’s upcoming appearance on NBC’s “Saturday Night Live” this weekend. Will Selena Gomez make a surprise appearance?

The teen sensation will be pulling double duty as the show’s host and musical guest, just as Maroon 5 frontman Adam Levine did two weeks ago.

After announcing that he would be the host and musical, Sudeikis argues plaintively, “Awe, com’ on, don’t you think someone else would want to do the music Justin?”

Jason means himself, of course. “You can do it next year,” Bieber says.

“You don’t know that!” Jason shoots back. “I m ready now; I have to do it now… My weight fluctuates!”

The promo cuts to two more scenes where Bieber and Sudeikis riff on Bieber fever.

Some details about the Bieb’s turn on the long-running comedy show have leaked. His monologue will be Valentine’s Day themed. Will he mention on-again, off-again girlfriend Selena Gomez?

It’s possible; there’s also an outside chance Selena may drop in on the show. She’s in New York City doing some promo work and attending New York Fashion Week, which is in full swing.

Bieber’s mom, Pattie Mallette, appeared on the “Today” show this morning and talked about his relationship.

For the musical portion of the show, Bieber is expected to sing “As Long As You Love Me,” and his new song “Nothing Like Us,” which is supposed to be his Gomez break-up song. It’s also one of the new tracks on his new Believe Acoustic album. Released last week, the album is already No. 1 on the pop charts.

Check out the promo below and follow TheImproper on Twitter for all the latest Justin Bieber updates.