I know Dopers can do this.
It’s a retelling of an Aesop fable - the Fox and the Crow (I think Ive got the animals right…). The fox is trying to persuade the crow to sing with his ‘lovely singing voice’ so that a tasty bit of food will fall from his mouth to where the fox can eat it. In this version, the crow figures out what the fox is up to, and doesn’t do it.
The last line is “Did you think I would fall for that silly old tr…”