I have a female friend, whom I've been friends with for over 20 years. Her 12 year old boy is very fascinated by my virtual reality gaming setup at home, and very often and very insistently asks me if he can come play and spend the night so he can play more the following day.

I'm a single man, 37 years old, and I live alone in my own house. I am not comfortable having kids spend time in my house without other adults present, preferably a parent.

So far I've been able to shut down the requests by stating that I don't have the time for it. But I want to shut this idea down for good.

To clarify: He's more than welcome to come and play, I enjoy sharing my interests with anyone like minded. But not kids alone, even if I have known them their entire life and is a close friend of the family.

How can I explain this to the boy, preferably in a way that won't make him sad or feel that I'm rejecting his friendship in general.