College rental with boyfriends spending many nights

[Patrick Donovan]

I have some new tenants living in my duplex and they are college girls. One of the girls has her boyfriend spending most nights with her. I don't mind it since they haven't caused any trouble at all yet ( Haven't even called me for anything yet), but I am wondering how you all handle this situation whether it be getting him on the lease or if there is an addendum I can make where he is a guest on the lease. I would like to find some way to make it where he is responsible for any trouble that he causes, but I wouldn't have to evict him if things got bad. I would like to know if this is even possible. Thank you all !