Hello Eric. My advice is that you decide what you want and make it happen. If peace and a drama free home is what you want, then you have to lay down the law since it’s your home. You tell your boyfriend and his nephew that they will either get some kind of conflict/anger management training so that they learn how to disagree in a way that doesn’t damage your home or your emotional equilibrium, or they have to go. If you anticipate feeling guilty for presenting this ultimatum, be proactive, do some research, find some cognitive techniques that will help you manage your painful feelings. Finally, take responsibility for your own emotional state. You bought this drama into your life and only you can fix it.