I think we must have been 13/14 and Nina had come to stay with us in Swiss Cottage, London. 
For some reason Nina had a French girl in tow. (I don’t recall her doing French??) the girl had absolutely no English 
My mother was out doing a locum up the road and the three of us had gathered loads of stuff for breakfast and settled down, in our pyjamas to play Monopoly.
Then the French girl needed to go to the loo and I forgot to remind her NOT to lock the bathroom door as the key kept jamming in the lock. Next thing she is hammering on the door crying and shouting and
Yep
The lock had jammed.
Ever practical Nina and I, with the dictionary told her to get the key out, pass it under the door and I would try and open it from the other side.
Bear in mind the window was not an exit option as it had burglar bars.
The girl managed to get the key out and pass it under the door and I tried to unlock from our side
And then
The key snapped 😂😂
Well Nina and I thought it funny. She did not
So I did what I thought was most resourceful 
And called the fire brigade 
THREE engines turned up. Sirens blaring. Blue lights swirling and who knows how many firemen piled in to the little house.
Their bright idea was to take a hatchet and smash the door in. So surrounded by breakfast debris and Monopoly money they set to after we told the girl to shelter in the bath under a towel to shield her from splinters 
And then my mother arrived home.
She was not impressed
But Nina and I laughed about it for years