Indeed.

Dear Dumbshit Children in the class I subbed for today,

Either your listening skills, or your powers of deduction/induction are terrible. From the start, I made it clear to you that my mother is the secretary to the disciplinarian. I will repeat that for you - my mother. is the secretary to. the DISCIPLINARIAN.

Why on earth would you think it would be a good idea to ask for a pass to the bathroom and then disappear for 15 minutes? Did you think I wouldn't say anything? Did you think I wouldn't notice?

And now you have detentions. Congratulations for thinking I'm stupid.

Love,
The Substitute Teacher You Now Hate