Ubisoft invited a bunch of young girls to come and play Just Dance 4 early for what they thought was a research focus group. The girls figured they were being asked to give some feedback on the game, but little did they know that Ubisoft had another trick up its sleeves.

Justin Bieber was called upon to help promote its upcoming game, by unexpectedly walking in on the girls while they danced their little hearts out. When he reveals himself, the fun really starts. As amazed as they are, they somehow manage to keep level heads. However, there's always one.

One particular girl broke into sobs and lost a tiny bit of her self control. Justin did his absolute best to comfort her, as we're sure he's an expert at this type of thing at this stage.

Good on you, Bieber.

Check out our Katy's Just Dance 4 review which is live now. We bet she is gutted that he never made an appearance while she was throwing some shapes at home.

[via nintendo-gamer.net]