My 7 yr old grandson, who lives with me is the poster child for oppositional/defiant. My parenting style and my granddaughter’s are so different. Besides everything being a battle with him, when he doesn’t get his way, he pees on things, poops on things, and breaks everything. He has broken his bed, desk, and chair in his room.No writing utensils can be left out anywhere. His mother won’t lower the boom on him, because she doesn’t want to deal with his defiant outbursts. I told her this was my house and my rules. How do I deal with this the most effect way? I am hoping she sees improvement and will be more open to dealing with him on other issues.