A leaseholder has a guest staying that is making the other roommate uncomfortable. What can I do as landlord?

Asked in Dallas, GA - 4 months

I have a rental property that each of the 2 bedrooms is leased and there is common living area. One of the roommates (#1) is complaining that the other's (#2) boyfriend this there, even when roommate #2 is not. I have asked roommate #2 about it, but she says boyfriend is not there when she isn't. Today roommate #1 notified me that #2 is not there but boyfriend is. Is there anything I can do? I asked that they talk about it together, but they just don't get along well. There is a clause for "quiet enjoyment". I don't really want to evict her, as she pays rent on time and this is the only issue. Thanks for any advise.