Me: Sister, are you wearing makeup?
My sister wearing all the world's makeup.
Sister: Just a little.
Hey, genius! The joke is that the sister is wearing a TON of makeup but says she's only wearing "just a little." It's funny because it's an understatement, which I know you don't understand because you are dumb. Now go back to watching your cartoons, and don't bother me again!
Makeup
Umm...