Well hey ! That's kind of personal.
I lied so much to my parents growing up it's kind of hard to pick the worst or biggest one. So here is a top 3 in no particular order :
1/ Once, in Belgium, I met this guy from an online community and we went for beers, it's so happened that that same night there was a big goth boat party going on and I really want to keep hanging. Unfortunately, I'm like 16 so I still needed mum's approval to do things you know. So I told my mum I'd be on my way back to the step dad's family house by 9pm or something and just turned my phone off as I was expecting an infinite amount of phone calls from there on. So I went on that boat party and when I came back from the boat, there was my parents...And the police. It goes without saying the rest of the trip wasn't my favorite.
2/ Short after, there was also that looong and tedious period of time where I'd tell my mum I'd go to school and instead I'd just go hang out with my friends, drink a bunch of coffee and beer, play Munchkins and soul calibur and come home with my backpack like nothing happened.
3/ And once, I stole my step dad's card because he hurt my mum and I went and bought myself a bunch of fancy super medieval gothy outfits and jewelry for my mum. When they accused me of it, I had to give it all back, it was super embarrassing.
So now that you know all my secrets ( no really, just a few,) I want to hear all about yours !