You shouldn't sneak behind your parents' backs.
Jen wants to go out on a school night and her parents typically do not allow this.
Jen wants to hang out with her friend.
Jen cleans up the whole house and approaches her parents with a good reason why she should be able to go out.
Jen slips out of the house late at night hoping her parents wont notice.
Jen's parents decide to make an exception and are impressed that she appears so responsible.
Jen's parents find out and ground her because they've lost trust in her.