Cut off your nose to spite your face
Definition 1 of 1
Pro Tip 1/3Emotional Impact
The phrase often implies strong emotions like anger or spite that lead to self-harmful decisions. 
In a fit of rage, he smashed his own phone to get back at his brother, essentially cutting off his nose to spite his face.
Pro Tip 2/3Figurative Use
Remember, this idiom is hyperbolic and not to be taken literally. It emphasizes the irrationality of the action. 
Refusing to study because he's mad at the teacher, he's just cutting off his nose to spite his face.
Pro Tip 3/3Avoid In Arguments
Using this phrase in arguments can seem accusing and escalate conflict. Use it cautiously. 
Telling her she's cutting off her nose to spite her face mid-argument might just make things worse.