In an effort to promote his charity, Water.org, Matt Damon went undercover as Santa Claus for a cause!
The actor talked to unsuspecting kids sitting on his lap about the importance of solving the world's drinking water crisis and encouraged them to give the gift of clean water!
Our favorite part is when Damon Claus asks a little girl, "If you were stranded in the desert, what would you rather have: this water bottle or Justin Bieber?"
Take a wild guess at what she would rather have! LOLz!
Defintely take a few minutes out of your day to enjoy the short and sweet video above!