I was standing in the girl's bathroom at school today, facing inside with my back facing to the door, so that people outside could see my back.
This one girl walks in and stops, and says really loudly, "OMG, Why is there a GUY in the girl's toilets?!"
Then she goes up to my friend, points at me and says, "Is that a guy?"
Without waiting for an answer she walks up to me and says, "Are you a guy?"
I say, "No."
And she gasps and says, "OMG, I'm so sorry! So sorry etc etc."
And then she goes and hides in the cubicle until we left.
It was so funny.