Filled with, or showing, spite; having a desire to vex, annoy, or injure; malignant; malicious; as, a spiteful person or act.

showing malicious ill will and a desire to hurt; motivated by spite; "a despiteful fiend"; "a truly spiteful child"; "a vindictive man will look for occasions for resentment"

do something negative to someone else at a (smaller) cost to yourself