Random people coming in and out

[Aaron Moore]

How do you handle a situation where the tenant constantly has different people coming and going from the unit? I know I can't tell her not to have company, but every time I stop by it's always people there even when she's gone. I also believe her boyfriend is living there and I told her that if he is then he has to be on the lease but I'm not sure how I can prove it without being there 24/7 and basically spying on them.