a dog in the manger

The phrase "a dog in the manger" refers to someone who spoils or prevents others from enjoying or benefiting from something that they themselves have no use or desire for. It originates from the fable of Aesop, in which a dog lies in a manger filled with hay, preventing the cattle from eating it even though the dog itself does not want or need it. It is used metaphorically to describe selfish or possessive behavior where someone obstructs others' access to or enjoyment of something simply because they don't want it themselves.