For me, it was always when my grandmother was staying over and my parents were away.
On one occasion, I snuck out to meet a boyfriend. Wild thing that I was. My grandmother was asleep.
On another occasion, I had a full on house party.
I suppose 20 or 30 of us. Smoking, drinking etc. Nobody in our house smoked and myself and my best friend spent about 3 hours the next day with windows wide open in all rooms and cleaned the place from top to bottom. My mother (the sniffer dog) never suspected a thing. My Dad had bought the alcohol for that party and knew I was going to be having it (18)!
What my mother did notice though was that our gates had a dent in them. My friend had tried to drive our geep and managed to reverse it into the gates bending them. We then had to get our neighbour to drive it back to where it had been (neither of us could drive). My mother said the seat was pushed back lol, so someone had been driving it but I just said I knew nothing. I denied any knowledge of that until I was about 35.
In general terms I was a very good kid!