Your response may help them be a better person.

While hanging out with a friend from her class, a boy that's not in the popular crowd, my daughter was asked:  "why are you hanging out with him?" (think of a bratty tween, and I'm sure you can hear how this sounded).  My daughter told me about it and was looking for advice on how to respond.  I refrained from saying "tell her 'its just say none of her business''.  Instead, I shared that she'll likely face these comments again, and her response can make the inquirer a better person.  I'm trying to teach my kid to be a better person, and in so doing, perhaps her actions will be contagious. I think this made sense to her, but I should probably read up on some 'bully' blogs, in order to help my kids be quick witted and to take the high road, at the same time.