FAN GIRL ALERT! Are all the tween girls still alive out there after these tweets? Canadian born heartthrob Justin Bieber and Australian singing sensation Cody Simpson hit up the studio together last night! The Australian posted:

chilled with the mate @justinbieber in the studio tonight. look for some great records coming. #AustraliaToCanada #CoastToCoast

while Justin responded:

alot of good people in the studio tonight. been working hard. tomorrow morning #MjForever

No more information on what the duo was working on, but a song with them together would be fire.

As if we needed more reasons to love these people! Selena Gomez and Big Time Rush came out to sing for charity at the 2nd annual UNICEF Concert. The Disney starlet and the Nickelodeon boyband, to the delight of all their fans, joined forces on stage for one spectacular duet! Check out the video above from the talented stars, as they cover “I Won’t Give Up” by Jason Mraz. Other celebrities who attended the event included Samantha Droke, Ashley Tisdale and Justin Bieber! Under the jump you can catch Selena’s hit “Who Says” and BTR’s hit “Worldwide”.

Justin Bieber answered some intense questions from his youngest & biggest fans! When asked what Justin and girlfriend Selena Gomez do on the weekends, his answer shocks the crowd and the screams are priceless! Check out the question video above!

Justin Bieber & Jaden Smith are at it again! This time, the teen power duo are releasing a much more slowed down and mature song: “Happy New Year”. The track starts with Jaden Smith showing off his rapping skills (Watch out Poppa Will!) and the song is taken over by a much more deeper voice… Justin Bieber! Justin showcases his new-found deeper voice in this wonderful holiday song that will forever become a holiday hit. Check out Justin & Jaden’s song above.

International superstar Justin Bieber performed an awesome version of his Holiday hit single “Mistletoe” for a group of very special kids. From the Martina McBride holiday special “A Home For the Holidays” which promotes adoption, check out the video above to see Justin’s performance.

Pop superstar Justin Bieber performs “Mistletoe”, “Away in a Manger” and sings along with “Hark! The Herald Angels Sing” at the Christmas in Washington event. After Justin’s performance, he is greeted by the President of the United States, Barack Obama. Check out the performance in the video above!

Here’s the new music video by Justin Bieber performing “Santa Claus Is Coming To Town”! The song, off Justin’s Holiday album, is also the fourth music video the pop sensation has released. Check it out above!

Big Time Rush sang “Beautiful Christmas” last night at the Christmas Tree Lighting Ceremony at the Rockefeller Center in New York City! The Nickelodeon stars rocked the stage as fans cheered like crazy. The group was not the only celebrity act, as Justin Bieber later came on stage with special guest Usher! Check their duet of “Chestnuts” in the video below!

Justin Bieber has ANOTHER new music video from his Christmas album Under The Mistletoe! Check out Justin with R&B queen Mariah Carey in their duet of Carey’s Christmas classic: “All I Want For Christmas Is You”. Check out the video above!