Small Balls

Alright, listen up, buttercup. So, the joke is about a "girl" who has "small balls". Usually, we think about guys having balls, right? But when you say a girl has balls, it's unexpected and kinda weird. It messes with your head because you're not used to hearing about girls and balls in the same sentence. And let's face it, you're not the sharpest tool in the shed if you didn't catch that.