Not particularly blue - but my favourite happened to a friend who was working as a supply teacher with children with special needs.
The local Macdonalds laid on a Christmas party for the kids and Kevin and another teacher were sent along to supervise.
One of the kids was hyperactive and was into everything - knocking chairs over, climbing on tables, running the length of the restaurant, he drove the two teachers barmy.
At about halfway through the proceedings the manager had organised a Santa, and he came in and began distributing gifts. The lad made a beeline for him, trying to pull his beard off, taking present from his sack, kicking him....
About five minutes later the lad came over to Kevin and said, "Hey sir; you see that Father Christmas?"
"What about him?"
"He's just told me to **** off".
Jim Carroll