Behind the ear isn't too terribly bad, I have a friend who got a butterfly behind her ear, and I didn't even notice it until I got up close to give her a hug. Other less obvious places would be your ankle, or anywhere along your leg if you don't wear a lot of shorts, or short skirts, or the back of your neck if you have long enough, and enough hair to cover it, and you don't like wearing your hair up. Your back and shoulder blades are good spots, too. I have mine on my ankle and my shoulder blade, because I wanted them to be hidable. Good luck!
