My next door neighbours have a grandson that spends a lot of time at their house. I told them when I started the daycare that he could come play by himself if I wasn't at my maximum number of kids, otherwise they will have to stay outside if he wants to play with the daycare kids. It has worked well being very upfront with it, there is no misunderstanding and they help me out too so we both benefit. They will supervise my own daughter outside sometimes so I don't have to (during non daycare hours) and they also walk home my school age kids sometimes as their grandson takes the same bus. I feel very lucky and grateful having this good relationship!