Completely agree. what I failed to mention is The tenant is my daughter and her boyfriend... otherwise I would never do a month to month verbal lease.

If you stay on the mortgage, you need to write out a legal agreement as to what happens when she sells (or if she finds another boyfriend/gets married). 

So recently my boyfriend/fiance I call him both was not living with me fully just staying every now and then and came over to visit a lot .

She finally did, and after 13 months, the tenant (and her boyfriend) left in a huff - just after New Years day.

As others said, one check with both names is the way to go.I had a similar situation last year with boyfriend/girlfriend.

TLDR: I'm buying out my house from my ex-boyfriend in Seattle (King County), Washington and I'm struggling to find what the REET if I'm buying my ex's stake in the house.

I charged them all the late fees and I was not happy and expressed my concerns, but I did get paid on the 12th.Now, this 3rd time for this month of August, the boyfriend contacted me a day or two before the 1st and said they would not have the rent until the 9th of August.

TLDR: I'm buying out my house from my ex-boyfriend in Seattle (King County), Washington and I'm struggling to find what the REET if I'm buying my ex's stake in the house.

Quote from @Chris Park: The risk of damage increases, but I would be more concerned with the fact she's bringing other men over while her boyfriend is at work, with or without his knowledge.

My current tenant wants to add their boyfriend to the lease.