Circa 1983 and I still cringe about it.
Girl sat next to me in a t shirt and her arm was resting on the desk.
I have arachnophobia and there was a fairly large spider on her arm and I instinctively picked up a text book and flicked it off her arm away from the pair of us.
She screamed and turned to me wondering what on earth I was doing and it was still on her arm and I stood up and started screaming, "It's on your arm! It's on your arm!"
She was looking at her arm as if nothing was there and was extremely puzzled!
I then thought in my state of fear that it was a dead spider and was somehow stuck on her arm.
My good friend who was also in the class, knew about my extreme phobia and came over to help and announced, "It's a mole!"
It was a large raised black mole with long dark hairs growing out of it.
It was horrendous as a few of the boys in the class were sniggering and the poor girl glared at me every time our eyes met.
Why the hell she didn't trim those bloody hairs, I'll never know as it would often catch my eye and make me jump.