WATCH: Mitt Romney's Son Called His Dad And Pretended To Be Arnold Schwarzenegger

Despite his often stiff demeanor, Mitt Romney has earned a reputation for being a prankster on the campaign trail. 

But the Republican presidential candidate apparently doesn’t like getting pranked back. 

In an appearance on Conan earlier this week, Romney’s son Matt told a story about how he pranked his father during the 2008 Republican primary by calling his dad’s cell phone and using the online voice tool Schwarzenegger Soundboard to pretend to be the then-California Governor, from whom Romney was seeking an endorsement.

Needless to say, Romney was not happy. We found this video of the prank online, and his reaction is priceless. 

Watch below: 

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