I just point blank told people that I would love to see them but staying at my house won't work. I told them I'd gladly make reservations for them at a near by motel and we can meet after breakfast and spend the day together. Most people are too polite to ask why it will not work so I don't have to go any farther. If they do ask I would tell them I am not comfortable with overnight guests. It is surprising how many people decide not to visit when they learn they don't have a free place to stay.

As for my friend, I would use my "husband" excuse. Whenever I want to say no to something but I think it will hurt someone's feelings I always tell them my husbband objects. He doesn't mind because I let him use me for excuse if need be. It always works.

If you don't make people feel comfortable they will not want to stay with you. Just be police and friendly when you tell them no. After all, it is your house and you make the rules.