He and they both know that this isn't a real question. It was bait for this exact response, meant to write these exact headlines. And its one of those baits that he has no real winning move against, with this probably being the least bad because its a simple "don't say that, its rude" like a dad admonishing a child.

But its on the same level as a reporter asking him "protestors said you pooped your pants, response?" Pathetic childishness meant to accomplish nothing.