tell on
Principiante (A2) informal
To go and tell a teacher or parent that someone else did something bad — or for something to start showing it's harming you.
"If you keep pulling my hair, I'm going to tell on you to the teacher."
To go and tell a teacher or parent that someone else did something bad — or for something to start showing it's harming you.
"If you keep pulling my hair, I'm going to tell on you to the teacher."