I could care less
This phrase is like saying you care a little, but you’re still kind of lazy. It’s like pretending to feel pain when you’re just kind of annoyed. You’re not really interested, but you still say you could be even less interested.
'I could care less about this dumb joke,' said the kid who didn’t even laugh.
'I could care less about the homework,' said the kid who didn’t even do it.
'I could care less about the test,' said the kid who didn’t even take it.