Tenant wants to add his ex wife to lease (who won't live there)

[Pria H.]

Hi all,

I rent out an apartment with 4 roommates who've been there over a year. Yesterday, we got an email from one of the guys asking if his ex wife that he is separated from, but "doesn't plan to divorce any time soon" can be added to the lease. The purpose is to have a shared legal address "for taxes and other paperwork". I didn't even know he had been married or separated. She won't be living there. 

Ordinarily the answer would be an easy "no", since the lease is limited to residents of the apartment, but I'm starting to wonder if their married status makes a difference.

I'm hoping that many of you experienced landlords out there have faced issues around married/separated tenants, and could share some insights.

Thanks so much!

Pria