Write a story ending with just then the principal walked in

Johnny had a rough day. He woke up 2 minutes before the bus arrived, tripped on the pavement, and got his jacket wet in the mud. Could anything go worse? As he sat down in his cozy chair in the corner of the classroom he felt a sticky substance latch onto his arm. “What could that be?!” he exclaimed with great force. Johnny proceeded to slowly move his arm so he could see what was clinging to him. To much of his dismay, a ball of pink sticky chewed bubblegum was resting snug in the middle of his arm. He screamed immediately and ran, for bubblegum was strictly forbidden at his school. He held the bacteria-filled ball with disgust as he rushed to the trashcan near the door. Then, the principal walked in staring straight at his pinched hand with the ominous pink bubble gum wad sitting pridefully between his finger.