For casual Fridays, my English teacher is going to show up naked.
Are they really going to show up at school naked?
Yes, I'm sure about it. My teacher is going to go naked on Fridays from now on.
You should tell someone about what your teacher plans to do. Them showing up naked is wrong since it will cause the people at the school to feel uncomfortable. It can also cause large legal troubles for them if they go through with it.
I don't think my school would listen.
I'm sure the principal would want to know. This has to be a violation of school rules somewhere. It would be strange if there wasn't.