The (autistic and otherwise special-ed) students I've worked with sometimes become inappropriate for various reasons.

"No thank you," "We don't do that," "That's inappropriate," and "(other student), get a teacher NOW," are all valid responses. Letting it slide? Not so much.

If you can consistently do it to your secretary and not your boss, you know better than to do it at all. For many, many values of 'it'.