Two parties on one rental agreement

When two parties appear on one rental agreement and one of the parties decides to up and leave, what is the responibility to that party that left, and what responsibilities remain with the party that satyed

If the lease states that both are jointly and severally liable, both parties are still responsible for the entire obligations under the lease. Moving out does not release a person from the legal obligations of a lease. The one who moves out is still responsible for his or her half. The one who remains can sue the other in small claims court to recover the money that is owed. The remaining tenant will still owe the entire rent to the LL, or both will face eviction.