That you’re going to spend the weekend unchaperoned in the biggest city in the UK with hundreds of people from the Internet whom you’ve never met. Oh, wait…

Seriously though, I’ve read a lot from people who’ve had this issue in the past. If you’re up-front and honest with your parents then it’ll also be a lot easier to explain why they have nothing to worry about; let’s face it, you’re not exactly gonna be breaking any laws or having your delicate soul corrupted by a huge gathering of Internet nerds. Plus, in the long run they’ll appreciate your honesty. But if they still don’t let you go then it’s better off to respect their concerns for your safety.

But if you feel like you have to lie, don’t ask us to help because if and when you get caught, we’d become partially liable. :P