How about when my parents are asleep, I will sneak out for a nightcap?
Why do you need to sneak out?
I just want to stop thinking for a while..
It is not a good idea to sneak out especially to drink. If you want to have some fun there are safe and legal things you can do to forget your problems for a bit.
So? I am an adult and I can do what I want to. If my parents are not guiding me, I'll be sure to find trouble.
I'm sure your parents care about you a lot and probably don't want you to drink and sneak out. You will get them so worried when they wake up and find you missing.