dog in the manger
Origin: From a fable in which a dog prevented an ox from eating hay he did not want himself.
dog in the manger - Cultural Definition
A person who spitefully refuses to let someone else benefit from something for which he or she has no personal use: “We asked our neighbor for the fence posts he had left over, but, like a dog in the manger, he threw them out rather than give them to us.” The phrase comes from one of Aesop's fables, about a dog lying in a manger full of hay. When an ox tries to eat some hay, the dog bites him, despite the fact that the hay is of no use to the dog.