New tenant wants to move in her Fiance with eviction history

[Jordan Williamson]

What do I do? I have a new tenant that presented herself as "just getting out of a serious relationship", single mom. The day after she signed the lease a guy started showing up pretty consistently. Now only two weeks into the new lease, she wants to move her fiancé into the rental. I said no problem as long as he fills out the application and is added to the lease; HOWEVER, when the application came back he has two prior evictions, bad credit, and drug and domestic battery offenses. 

Obviously I don't want to add him, but I am concerned with the repercussions of not letting him move in to his finance (and baby momma's) new place. One positive is that he seems to have a steady good paying job.