Legal Question in Landlord & Tenant Law in California

Re: Rental Lease

A lease is a contract between or among the parties originally signing it. If the spouse wishes to sign, it would be an amend to the contract or a new contract. The landlord technically could refuse to let the spouse sign, but why would the landlord do that? Unless the contract states that there is a limit of one person who can live in the unit [as opposed to your merely stating to the landlord that there will just be one person living there], then the limit on the number of people is what would be reasonable. I think it would always be automatically reasonable that the spouse would also live there. Since the landlord knows the spouse will live there whether or not they sign the original contaract, why would they refuse to have another person responsible for the lease and rent? If the landlord has actually told you this, what reasons did the landlord give?