That's very sad - you have every right to be mad and angry. It's horrible to do this to any living thing...animal or human. I also agree with the other poster about what will he do if he gets fed up with your mom or you. I think you should secretly call animal services. This is also your mom's house and the dog should be allowed to come in the house. I would even say it's better to give the dog up, if Matt can't be 100% safe. I know this sounds extreme but I would rather see a dog put up for adoption, rather than get abused. This really makes me so mad(grrrr) and I'm sorry you had to see this.