Honestly, if you don't know the person you have nothing to worry about, because most of the time you'll never see them again. I've gotten used to utter embarrasment in public. Eventually it's not embarrasing anymore, and people just note your animation and eccentricity, chuckle about it, and forget. It makes it a lot easier to be yourself wherever. Also, just because someone saw you doesn't mean you have to feel shame. You are your own judge. It's not shameful to express yourself when you think your alone, and unless what you think you do is shameful BEFORE someone saw you, then it's not shameful. People can deal with it, because you did nothing wrong.