Home alone. We've all seen the stories. Parents go away overnight, leaving an empty house. Teenager invites a few friends over.
It's something you worry about, as a parent. It's on the list with late-night muggings, random knife crime and spiked drinks. But it's pretty rare.
I'm not saying it never happens. My friend went next door at 1am when the shouting and screaming got too much. Her neighbour's 17-year-old didn't want to let her in at first. She pretended her parents were upstairs asleep. My friend wasn't fooled. She said, "Let me in or I'll call the police."
It was the right call. An hour later, when drunk revellers had been packed off home and the worst of the mess was in black bin bags, the 17-year-old burst into tears and said, "I was really scared. I didn't know what to do."
But for every horror story about a Facebook party that leads to cigarette burns on the duvet and raw egg on the carpet, there are 99 untold stories about nothing happening at all.
Most of the time, if you go away for a night and your teenager is old enough to be left alone, you'll come home to nothing more appalling than cold pizza crusts on the kitchen table and a pile of washing-up in the sink.
Of course, it's wise to set down some ground rules before you go. Something on the lines of:
1. No parties
2. No parties
3. No parties
But after that you're probably OK – as long as you prime the neighbours to keep an eye out for trouble, and keep your mobile glued to your hand.
The worst thing that ever happened in our house was my son having two of his male friends over when we were away. It got so late that no one could get home. So he took the sofa and said airily to his mates, you can sleep in my room.
But his directions weren't that good. So they ended up in our bed.
You don't want teenagers in your bed. I won't go into detail. But you really don't want teenagers in your bed.
Sometimes, in idle moments, I wonder what his friends thought of his bedroom, complete with dangly earrings, bottles of scent and a bra drying on the radiator.
You can catch up on more Surviving Teenagers columns here.