Couple breaking up, both on the lease

[Jim Bryant]

I have a couple renting one of my units.  They are both on the lease and have been together for years but are now breaking up.  The female wants the guy to leave and to be kicked off the lease (the lease is now month to month).  She says that he isn't paying his share anymore.  

We can't prove anything from our angle and she is always the one who calls us.  The guy seems to have some sort of anxiety, as he got really upset when we moved them out for two days to fix something with the house to satisfy the county (at our expense, of course).  She said that he won't talk to us on the phone, but since she's the conduit, she could be full of it.  

The couple have been good renters and have not caused any problems.  I was reading up on what to do with a roommate who refuses to pay their share and one of the steps is to go to the landlord.  But, I don't feel like we should get involved in any of this and simply continue to collect rent and tell them to work it out amongst themselves, since we can't prove anything one way or the other.

Anyone have any thoughts on the subject, or experience?