Well, I have noticed this trend where I live, for kids to just go spend the night with people their parents have either never met, or barely. Never having seen my house, we have had at least 4 kids spend LOTS of time over at my house. It baffles me that other parents let their child spend the night (or days at a time) when they have barely met me, never met my husband, and don't know WHAT kind of environment we live in. Most of these kids, however, live in shabby surroundings, with what I consider questionable goins-on in their homes (usually unruly teenage stuff) that I am glad to get their kids out of it anyway. My kids have not spent the night with THEM though!
The only friend my daughter has spent the night with since we moved here 3 years ago, it did not end well. I went against my little voice and regret it. But I had met the parents several times at school, knew they had an infant son, and had seen their house - although small it was well maintained on the outside and not a bad neighborhood. But after spending the majority of the weekend with this child, we came to pick her up on Sunday morning for church. We had called an hour before and told my daughter's friend (who is 8 and answered the phone) that we were on the way and my child needed a shower and to be dressed to go. When we arrived, the mom was 'asleep' on the couch, the baby was crawling out the door when his sis answered, and the girls had fed themselves chicken soup (opened the can and microwaved it) for breakfast. They had also taken a bath - WITH the dog! - but then put sticky play makeup all over their faces. Turns out, even though they never indicated this at parent meetings, the parents are separated, and the only one watching these 3 kids was a woman who turns out to have an alcohol problem and was still hung over when we got there! My judgement was WAY off this one time, but I learned my lesson! Other people may entrust me with their kids, but the ones who do, I know that I wouldn't let my kids stay at their homes.
You will never regret being too careful, although others may say you are too overprotective. Kids will eventually recognize that as how much you love them, not a trust issue with them personally. My kids are 11, 9 and 8 now, and they are probably going to find me as a drag when they are teenagers, but oh well! As long as their friends can come with us and have fun, it shouldn't be an issue....
And like some of the other Mamas said, if people have a problem with you staying, they shouldn't be trusted. It may be that they are just embarassed their house isn't clean enough or big enough (even I don't want very many people seeing my messy house sometimes), but they can just accept that or arrange a public playdate!
God Bless,
A. V