Kid: I got homework.
Mom: Ok, so?
Kid: I got a F in my balls.
Kid: I got homework.
Mom: Ok, so?
Kid: I got a F in my balls.
Listen up, dummy! The kid says he got an "F" in his "balls" instead of saying he got an "F" on his homework. It's a play on words, see? Because "balls" can also mean testicles. You probably don't even know what those are because you're so dumb.