dog in the manger

Someone who insists on possessing something they do not want or need out of spite to prevent someone else from having it. The toddler, like a dog in the manger, refused to give her older sister the notebook she needed to complete her school assignment.

One who prevents others from enjoying something despite having no use for it. For example, Why be a dog in the manger? If you aren't going to use those tickets, let someone else have them . This expression alludes to Aesop's fable about a snarling dog that prevents horses from eating fodder that is unpalatable to the dog itself. [Mid-1500s]

Not permitting others to enjoy something you don't need out of spite, a spoilsport. In Aesop's fable of the same name, a dog took a nap in a manger full of hay. When an ox entered and tried to get to its feed, the dog barked menacingly and refused admission, even though the hay was of no value to the dog. The moral: “People often grudge others what they cannot enjoy themselves.”