I Couldn't Resist the Prank

Last week at work, I couldn't resist setting up a silly prank on my coworker. I knew he loved his Star Wars coffee mug and would never dream of touching anything else in the morning. So, when everyone was out for lunch, I switched it with an empty one that looked exactly like it from the front. When he came back, he stared at it confused before finally realizing what happened. He wasn't happy, but secretly I thought it was hilarious.