Some schoolboys were chatting on the playground showing off about their growing dicks.
'Mine is six inches' said one.
'That's nothing mine is eight inches' swore another.
Finally the third one shamed them both; 'Mine's ten inches!'
Unbeknown to the trio a young female teacher overheard their covnversation.
'I think you boy's are a disgrace' she said. 'Don't you know we've gone metric?'