Pranked the 13 year old this morning.  He's like me, not much of a morning person, and he waits until the last minute to get up.  I told him that his dad had gone out for donuts this morning, and he was downstairs in record time.  Very shortly he came stomping up the stairs, asked me where the donuts were, I said downstairs, and he said "that's not funny" and stomped around some more and slammed a door or two.
I thought it was funny!