I don’t see how that’s any of your business.
A magical phrase that makes people stop talking, like you cast a spell on them.
Your mom asks why you're crying. You say it's none of her business. She walks away confused.
You get caught eating your teacher's eraser. You say it's none of their business. They don’t believe you.
You get asked why you’re wearing socks in the pool. You say it's none of their business. They laugh at you.