period erection

Why this is an exclamation point of course! It is a period that is in a state of enthusiasm. It has nothing to do with vulgar sex stuff or menses.

Teacher: "Okay class. Today we will learn about the exclamation point and what it means. Understood?"

The teacher then draws one on the smartboard.
Ernie: "Umm, Miss B? Why does your period have a boner? It's like a period erection or something!"
Class laughs.
Teacher: "That's enough, class! Ernie! Get your hands out of your pants! You little pervert! Stop staring at my chest!"