Tought a 9 year old how to play pong

So for my summer job I babysit one kid that turned nine this year.  And it was too cold and windy to be outside at the beach, so we decided to stay inside and play some games.  We played a few games of whatever and then I came up with the idea to teach the kid how to play pong.  They had a ping pong table in their basement so i chose to set up there.  I set up the cups and instead of beer we used water.  Took about ten minutes of explaining the rules and how to play and what to do, but when he got the hang of it he could not stop playing.  haha so at work i was playing water pong for 2 hours straight.  And I am teaching this kid some good valuable lessons for his upcoming years.  And also it's not bad that i can get to practice at work for later that night.