Kyle Chalmers' grandparents' reaction to his gold medal is priceless

— -- Get ready for all the feels. 

The 18-year-old Australian swimmer Kyle Chalmers had a pretty good run in Rio, including taking home gold in the 100-meter freestyle. 

His grandparents watched his performance from home, and to say they were proud is an understatement: 

Our favorite part of the video? "C'mon, boy, get those flippers going!"