Sour grapes is the action of making something seem less important after finding out they can't have it.
An example of sour grapes is a man saying he didn't want to date a certain woman because she was dumb, after she decided to date someone else.
a scorning or belittling of something only because it cannot be had or done
Origin of sour grapesfrom Aesop's fable in which the fox, after futile efforts to reach some grapes, scorns them as being sour
Denial of the desirability of something after one has found out that it cannot be reached or acquired: The losers' scorn for the award is pure sour grapes.
(uncountable) (plural only)