You left the math room to go to the toilet, when you started going about your business, a tall high school student comes into the toilet.

You are surprised and ask him

“Dude, this is a women's bathroom, what the hell are you doing here?”

it turned out that some idiots occupied the men's room, from which the guy came to the women's room, because he had no other choice.

Chatting sweetly, you became friends, but then when the head teacher entered the toilet, you quickly pushed him into the stall, and also hid with him

Then he says in a hoarse voice

"Don't cling to me too much~, my friend is already at the limit.. ~"