Husband requesting deposit back but divorced wife still stays

[Jimmy Tao]

I've run into a situation like this: The guy signed a lease with me to rent the property. Later he married and the wife moved in. Now the man says he divorced, moved out. He requested his security deposit back although his ex-wife still live in the house. The ex-wife paid one time the rent under her name. I did not notice until the husband demanded his security. Wife obviously doesn't want to move out but doesn't want to pay for the security deposit either. Appreciated if you have similar experiences and would like to share the ways to handle it.