Besides, I don't think he's her boyfriend per se as much as a casual visitor who visits every so often LOL.

If its a standard CAR form that your lease is written on, you will have the language about not running a business from the rental unit as well as language about visitors.

I always make sure mine has late fees spelled out and also rules on what pets they can have and how many visitors and for how long those visitors can stay.

That can be tedious but the only way.Also ensure that your doctor or heath facilities you visit or plan to visit takes that health particular plan, before you sign up.Unfortunately, no one in either parties elected or running for office been able to fix health care in the US.

It's when they are not neutered that the male cats spray that disgusting whatever-it-is all over the place.We also mention new pets and visitors pets and fines for each.  

I could either pay a visit or send a letter.What do you recommend?

Oh, will your insurance pay should a visitor get bitten by that dog!!!

Now we just have to try and keep the visitors from coming back at night.

When I asked about her (we thought she was over 18), because male tenant said "we are thinking of having her stay with us for the summer" (violation of lease which says visitors can stay 7 days), the female tenant replied "he misled you, sister visits for help with homework, she spends the night sometimes".  

Same lease as everyone else--how many visitors, how many nights a month, etc.