My children are not good with strangers.
To be fair, however, neither are Chris and I.
But I'm not sure that "shy" is exactly the right word to describe their behavior.
Sam is terrified of you and a little ashamed that he doesn't know you. If forced to interact he will be near tears; sad and anxious.
Owen is angry at you for even have the audacity to BE a stranger. If you're lucky, he'll make a slow swivel until he has turned his back on you. If you are an especially egregious stranger, he will lower his chin and glare at you, accusingly. How dare you. Really. Do you know who he is?!
Chris and I have our own methods. Chris is a fan of the old, "quite practice-talking that's weird because people can actually still hear it" technique, while I prefer to awkwardly avoid eye contact.
Our children are DOOMED.