i don't care
A way to show you're completely uninterested and probably mad about something else.
You: Are we going to the mall? Me: I don't care. You: Why? Me: Because I'm mad about my dog eating my homework.
You: Do you want to go to the party? Me: I don't care. You: Why? Me: Because I'm mad about my mom yelling at me.
You: Do you want to do anything fun? Me: I don't care. You: Why? Me: Because I'm mad about my friend failing the test.