Steal someone's thunder

Meaning

To take credit for someone else's idea or to draw attention away from their big moment. It is the social equivalent of jumping in front of a photo op.

Annoyed, descriptive

Used in a sentence

• I wanted to announce my engagement, but she had to go and share her pregnancy news at the same dinner.
• Don't you dare reveal my promotion before I get to tell my parents.
• He always loves to steal someone's thunder by bringing up his own projects during your big presentation.