I know you said the house is crazy but is the mother at least around?
This thread has me thinking back to when I was a kid, and the most trouble I ever got into was when sleeping over at kids's homes who were very well-do and the parents seemed disengaged, and sometimes off in some other far area of the house that I didn't even see them the entire time I was there. I'm talking ages 12-14. Sneaking out at all hour of the night, drinking, smoking pot for the first time, etc.
But, those were a lot fun.