Yep i agree, go tell the parents.
I've been to a little boys house twice who lives up the road as , once he was standing on the garage roof,(which overlooks a glass house), and another time he let himself into our garden,(it's walled), and i found him sitting crying and my boxer dog licking him!!!!!!!!!!!!!!!
His mam was great, he hasn't done anything since (fingers crossed)
Good luck+++++++++++