Can I, as a resident, restrict a family member’s entry?(New Jersey)

r/

I’ve tried Googling this question to get a rough idea, but I couldn’t find anything that applied to my exact issue.

Since last year, I’ve been my grandmother’s full-time caretaker. She has late stage dementia, and my father has power of attorney, but only I’m here living with her.

Occasionally, my aunt and cousin will visit. While I understand them wanting to see their mother/grandmother, they’ve been getting increasing ruder with their visits.

They show up unannounced, sometimes as late as 11pm, and treat this as their hang-out for speaker-phone calls and blasting YouTube videos. Half the time, they leave a mess for me to clean up (putting cartons of juice back in the fridge is beneath them, I guess).

And this is apparently a game to them because last night my cousin was laughing with his father on FaceTime about staying until midnight.

I eventually snapped, kicked my cousin out, and made a police report. He had left his parental grandfather in the car while chilling watching TV as if he owned the place.

I understand that being a jerk isn’t ’illegal’, but it’s starting to get ridiculous that chaos can just show up at my door and I’m stuck being their butler while they treat me as if I don’t exist.

Of course, my cousin is being indignant about this. My father had given my aunt a key a while back, and my cousin believes this entitles him to visit his grandmother whenever he pleases.

My parents are conflict avoidant, and I have no idea when/if they’ll get involved. I tried to ask them to talk to my aunt (since she won’t call me), but I never got an answer back, and I’m tired of being treated like a coat rack.

As the person living here and taking care of the household (but not the home owner), am I allowed to just change the locks and not let them in at weird hours? I feel like calling before stopping by is a reasonable request, but do I have legal ground to tell them to get lost if they want to be horrible guests?

Location: New Jersey