Gosh!

Young Bobby McGillicuddy was the luckiest boy in the world, for he was the proud owner of an invisible tail which he used to poke people with on the bus.

One day Bobby was travelling to school on the bus. He had a whole seat to himself because as well as his tail he also had an alarming habit of wetting his pants whenever the bus brakes squealed. However, as Bobby was enjoying his big seat a very fat man got on the bus and sat down next to him.

Aha, thought Bobby, this looks like a job for my tail!
Very carefully, Bobby sent his invisible tail around behind the fat man, and poked him. The fat man jumped in alarm, then looked around to find two nuns in the seat behind him. Instead of starting a fight as Bobby had hoped, the man sat down again, pulled his briefcase onto his lap and started sweating a lot. Bobby used his tail to poke him again but it just made the fat man breathe harder.

Bobby decided to use a different strategy. This time, he used his invisible tail to poke one of the giggling high school girls in the seat in front of him. The giggling abruptly stopped. One of the girls looked over the seat at Bobby and the fat, sweaty, breathing man. She screamed. The fat man jumped up, and his briefcase slid from his lap. The girls screamed harder, and one of the nuns fainted. The other, battle hardened, punched the fat man in the nose. The fat man attempted to run, but he was too large to do much more than waddle awkwardly towards the door, with the eyes of the etire bus upon him. Bobby was once again enjoying his nice comfortable seat when the fat man reached the front doors and the driver hit the brakes.

There are some things even an invisible tail can't fix.