Don’t you dare!
Definition 1 of 1
Pro Tip 1/3Strong Warning
Expresses a firm command or warning, implying consequences if ignored. 
Don't you dare talk back to me!
Pro Tip 2/3Emotionally Charged
Often shows the speaker's emotional investment, such as anger or protectiveness. 
Don't you dare hurt her feelings.
Pro Tip 3/3Casual Speech
Mostly used in informal situations among friends, family, or peers. 
Don't you dare spill the beans about the surprise party!