Tenant Lie Number ##?

[Demetri T.]

I have a lie that I haven't had to deal with before and my inherited lease is silent about.

Tenant is a section 8 tenant who has approval for herself and her two kids.  However, there is another guy there nearly all the time.   Tenant assures me he is not "living there", that he is the children's father and is there a lot but he sleeps somewhere else.  I have been driving by and he seems to be there just about every time I drive though- early morning- early eventing- throughout the day!  (Though I haven't gotten up to go check in the middle of the night).  He does not necessarily cause trouble (so far a I know) but I am getting the impression he could not pass our background check not to mention the Section 8 thing.

I believe I have tried being reasonable with her and asking her about it and now I am pretty sure she is just lying about him "living there".

I am not opposed to trying to talk to her about it one more time before I just send the notice to her and the housing authority- though I think that would get her in a lot of trouble.  

What should I tell her in may last ditch effort to be the overly reasonable landlord?  Do I even bother trying to be reasonable? Other ideas?