One tenant moved out suddenly leaving non performing tenant in property

[Josiah Horn]

Background: purchased property with inherited tenants. Tenant had bf living with them I made bf sign lease amendment to be on lease. 

Tenant informed me they would be leaving February first. (M2M Lease)

A couple days later Tenent texts me and says they have left the property effectively today (bf doesn’t help out with bills, drama, etc). and wants off lease. 

I obviously have no interest in boyfriend staying as they are constantly a week late on rent and I suspect to not receive another dime moving forward. As rent is officially late today can I just serve a pay or quit notice asap? Do I have to let leaving tenant off the lease? I feel like it would be easier to get bf out if they are both at risk of an eviction but obviously legaly questionable… I just want it empty :(

(Currently trying to get a hold of boyfriend for his side/plans/expectations)