Ellen and Justin Bieber just pulled off the most hilarious prank ever

He shocked everyone when he appeared on The Ellen DeGeneres Show last week, to apologise for his recent bad behaviour and to assure his fans that he was turning over a new leaf.

While some people are waiting to see if he holds true to his word before making a judgment call, one person who seems to be supporting him all the way is Ellen herself.

Indeed, Ellen is so delighted to have the old, sweet Justin back that she decided to welcome him back onto the show for a truly hilarious prank.

In what has to be one of our favourite Ellen pranks of all time, she and the Biebs are seen hanging out in her studio’s toilet cubicles, waiting to shock unsuspecting members of the public.

What makes this prank so good is their inventive ways to really up the shock factor, from pretending to be caught up in a romantic clinch to performing wacky musical routines.

Check out the video below, and prepare to laugh. Wait for the hilarity at 0:52.

That woman is such a genius!