Ditto the above. I divide kids into three basic groups and treat them differently based on that.
Kids about 10 and over: treat them like adults with very short attention spans. Shake hands when introduced, use real words/sentence structure, be respectful, answer questions asked, etc.
Kids between 3 and 10: same as above, but no hand shaking (they don’t get it yet). Silly questions are good (“so you must be 30 now, right?”). For some reason, they think it’s funny. For what it’s worth, this is the best age group to ask questions about how much things cost. They have no clue, and (I really don’t know why) for some reason it just cracks me up. Ask a 5 year old how much his new shoes cost – “a hundred dollars!” – and dad’s new car? – “a hundred dollars!” – my house? – “a hundred dollars!” Yes, my life is pretty barren that I find that funny.
Kids under 3: follow the parents’ lead. Don’t be afraid to ask questions (“do I have to support his head?” is okay; “is she supposed to look like that?” isn’t). If you’re uncomfortable with the kid, walk away.
Stranger, I’ve never thought about making sure that the parents are in the room. I figure I’m not going to do anything wrong, and they know that (or they wouldn’t leave the kid with me). Plus they know their kids. One friend’s kid loved an escort to the bathroom once she learned how to use the potty. My friend would just shrug, and let her hapless guests be dragged off, one by one, so that the kid could show off how well she could use the potty.
I’ve thought that was weird, but I never was concerned that I would be suspected of doing anything nefarious. My friend knew the kid liked to show off her potty skills, so wasn’t concerned about the escort issue.
Having to be careful about being alone with kids is kind of sad, because kids are so open with people, usually. But I guess that’s the world we’re in now.
So, dotchan, as long as you aren’t a “pervie kiddie fancier,” you’re likely safe.
But if you want to be extra safe, keep the parents in the room. And if the kid wants to show you something in em’s room, tell the parents – “hey, kiddo here is going to show me that Dr. Seuss collection – want to come along?” If the parent has any concern about you being alone with the kid, the parent can tag along, and you haven’t broadcast your concern that you’re going to come off as a perv.
But relax – in some ways, kids are so much more forgiving than adults about social awkwardness. What you perceive as your own ineptitude around kids, the kids just perceive as the way all adults behave. So relax and have fun.