The Monkey and the Cat.

by Aesop

A MONKEY and a cat lived in the same family, and it was hard to tell which was the greater thief. One day, as they were roaming about together, they spied some chestnuts roasting in the ashes. Come, said the cunning monkey, We shall not go without our dinner today. Your claws are better than mine for the purpose; you pull them out of the hot ashes and you shall have half. Pussy pulled them out one by one, burning her claws very much in doing so. When she had stolen them all, she found that the monkey had eaten every one.

Moral:
A thief cannot be trusted, even by another thief.