When does curiosity become rudeness?

Short & Curly listener Luca often gets stared at when he is in his wheelchair. His parents think the people who look too long are just being curious but Luca thinks it's just plain rude. So when does curiosity become rudeness? And how can we be curious about someone's difference without hurting their feelings? Brain Trust — Casuarina Street Primary School, Katherine: Bruno, Leilani, Eloise Lawson, Lexi, Kodah