Ugh, that's such a hard one. You really never quite know what to say. It makes me really angry when people ask that question as its really none of their business at all. But I'm just too "goody two shoes" to tell them where to go. It just really hurts. I like the idea of asking them back why they are asking this in the first place as it really is none of their business and they should have that basic respect for the privacy of other human beings. I ALWAYS wear long sleeves, no matter what, but sometimes your sleeves fall back and you just find someone staring at your arms. It really stinks. I hope you find a way to deal with such insensitive, probing questions in the future. But remember, they're being the arses and not you.