I just had to deal with this in Texas. It was a NIGHTMARE. Tenant had a lease allowing 2 adults and 3 kids.( though only he lived in the house) Unknown to me he rented out a room to a co-worker. Shortly after, co-worker's new girlfriend moved in. Not long after they have a big fight (cops are called) and he leaves. Girlfriend stays. I find out about the cops being called from neighbours. I speak to tenant and get the whole story. I tell him she must go or go through application and lease process. Find out she has a serious drug conviction and tell tenant she doesn't meet standards and she must go. She causes a MAJOR incident and gets tenant arrested for domestic violence. I terminate lease. Next day after he posts bail tenant moves out. I think THEY have moved out and have elec put in my name so I can get the place cleaned up and show it. However, when I go to enter and change locks etc... SHE is still there, calls the cops and claims residents rights. Turns out I can't charge her with trespassing because she has moved personal belongings into the house and is now considered a lawful resident. I can't change locks without giving her a key, I can't turn off power, she can get water turned on and I can't stop it. I had to go through full eviction proceedings to get her removed. Took me 40 days. She trashed the house and had every light in the house on and AC set at 70 during the whole time. Electric bill was over $500.00. Called the cops on me twice. Used the place as a "high" house.
You can do what you wish but I will never turn a blind eye if I ever have a similar situation and find out about an unauthorized guest and my lease now includes VERY specific clauses regarding "guests".
Vic