Legal Question in Landlord & Tenant Law in Massachusetts

An overnight guest is usually permitted for a limited number of nights and there needs to be a published rule or a prohibition against overnight guests in a lease to prohibit any overnight guests. It is one thing to prohibit someone from staying in an apartment for more than a week and a prohibition against visitors staying at all. You are entitled to reasonable use and enjoyment of your apartment including overnight guests without it being deemed as having an unauthorized occupant of the apartment. So if your cousin from Cleveland visits for the weekend, that should be permitted. If they want to stay for a month, that is something different.