In primary school, our homework was to find out something about Henry VIII, so I went home and asked my sister if she knew something about Henry VIII, and she did.
The next day in class I keenly stuck up my hand when we were asked what we'd found out and proudly repeated what she'd told me: "All his wives were whores, sir!"
(In my defence, I realised almost immediately that "whores" was a word I should know the definition of before using in public again.)
---
In secondary school, when we were asked to write a letter in French, I wrote at the top of the bit of paper: "A French Letter", which made our teacher, Ms. Cathro, giggle a lot. I asked her what she was laughing at and she told me to ask my mum. I asked my mum, and she giggled and told me to ask my sister. I asked my sister and she giggled and wouldn't tell me. What a bunch of giggly bastards!