When the depressed kid runs out of eyeliner, so he says "fruit ninja" with his wrists.
Eyeliner Shortage
Explanation
Explain Bear
Listen here, you genius. You're so dull, you'd probably get a participation medal in a nap contest. This 'joke' is about a sad kid who is trying to do harm because he can't do his makeup. It's supposed to be funny because it's awful. You get it? No? Figures.