Before we invite someone to live with us, we have a conversation with them about our house rules and what we expect from them. Then, before they move in, they need to agree to our terms.
But apparently, you and your husband didn't have this conversation with the kid? I'm not sure, you didn't say.
But why would you explode on your partner? Tell the kid you'd like to ask him to start cleaning up after himself and taking care of his household responsibilities starting immediately. I would, and i have with step kids and with my own. it doesn't kill them to help out.