Is it legal for a home insurance company to require renters insurance for a domestic partner?

NYS….When i mention it to other brokers they say it is not necessary and are surprised that they are requesting it. I don't see the reasoning behind it other than another way to bilk people. He does not rent and is not a tenant.
I had Allstate and they are not renewing due to hurricane risk. Go figure.
This may sound unusual but The contents are not my concern. I just want home owners insurance because the mortgage company requires it. To require me to have anyone living with me to also get renters insurance seems fishy. why would someone be able to sue him if they get hurt? Wouldn't they have to sue the owner of the property?
Thanks for your answers but you guys are making me paranoid. You're better off living alone and not having any visitors.just in case something should happen….which probably never would anyway.

From a Multi-Line General Agent

"No", It is not legal for your Home Insurer to require your domestic partner to obtain renters insurance unless they are actually a "Renter". It may also not be Illegal in your State of Residence. It is however definitely Unethical. If they do this, Then I would strongly recommend you find another more reputable Insurance Company or another Insurance Agent because I can assure you, they are just trying to milk you for more premium.

A domestic Partner is not a "Renter", they are a household member and a resident of your home/ No additional or separate coverage is required to cover them or their contents on your existing policy. A "household member" or "resident" does not have to be a blood or marriage related "family member" to be covered.

There are plenty of Captured Insurance agents out their that would like to scare you into buying additional coverage when none is needed. Remember that Insurance Agents work on commission, So the more you pay in premium, then the more commission we make.

Such a requirement is highly unethical and as a General Agent I would cancel any appointment my agencies have with that insurer and would no longer offer their product.