Tenant's Ex and New Girlfriends Drama

[Filmon Michael]

I need your wisdom on this interesting situation. I have a month-to-month tenants, a man and his ex-girlfriend. He is a handyman who takes good care of the house. They broke up two month ago. Meanwhile, he has been paying full rent but his ex is not contributing anything to rent and she refused to leave the house. Now, he got a new girlfriend and wanted to live together in the house, but his non-paying ex is there. So he asked me to add the new girlfriend in the lease and remove the ex from the lease so the ex leaves. Although this is personal matter, it will surely affect rent payment and my income. I want to keep him in the house, but with all this drama I have no idea what to do. Please advise. Thanks!