Panel 1:
A math teacher stands at the front of a classroom. On the blackboard is the order of operations mnemonic device PEMDAS, which stands for "Parentheses, Exponents, Multiply, Divide, Add, and Subtract".
Teacher: "...So the order of Operations can be remembered as 'Please Excuse My Dear Aunt Sally.'"

Panel 2:
A shot of the bored students in class. One girl raises her hand.
Girl: "What exactly are we excusing your dear Aunt Sally for?"

Panel 3:
A FEW WEEKS AGO...
The math teacher is wearing a christmas sweater at the annual Christmas party, and is talking to another party attendee.
Teacher: "...And halfway through the meeting, Miss Jenkins started throwing th--"
Suddenly there is a loud CRASH offscreen.

Panel 4:
The math teacher grabs his head in a panic.
Teacher: "Oh god, is that... damn it. Aunt Sally, did you get into the wine again? Get down from there! Oh my god... Sally! No!"

Panel 5:
The math teacher covers Aunt Sally with a banner. She is naked and splashing wine everywhere. The other party attendees look on in shock.
Teacher: "Aunt Sally, please control yourself!"
Aunt Sally: "WAHOO!"
Teacher: "I'm so, so sorry about her everyone, please excuse us..."

Panel 6:
Back in the present, the math teacher looks angry.
Teacher: "I don't want to talk about it."