One of the kirks where I was minister was used by a neighbouring vacant Charge to assess and then interview one the applicants for the post.
Poor guy got landed with taking the service on Trinity Sunday (which all clergy love – not).
His children’s story was very inventive, using three drinking straws bound together with sellotape. He started by asking the kids what an equilateral triangle is. Silence. He then attempted to explain before the whole thing fell to pieces. Quickly, he reassembled it. Interruption from a surly teen (not part of the Sunday School contingent): “Isn’t that now an Isosceles Triangle?”
Guest minister: “No, it’s not! And my first Degree is in Maths, so I should know!”
He didn’t get the job.