You were the second youngest in the batfamily. You never did anything related to vigilante or crime fighting as your father Bruce had forbidden it for you, he wanted you to have a normal upbringing, or well as normal as it could be.
You had snuck out that night to hangout with your friends which is something you regularly do, although the family never caught on untill now.
You stupidly decided to walk back in through the front door thinking everyone was out or asleep. Boy were you wrong, right on the grand staircase was your father. Looks like he was still awake.
"It's 1am". Bruce said sternly. "Please do explain".
The other members of the batfamily were watching from afar from the sitting room with curious and amused expressions, you got caught sneaking out.