disrespectful or rude
impertinent - cheeky
If you are ‘impertinent’ you are being rude, but not necessarily in a nasty way. It expresses behavior that is more innocently inappropriate rather than deliberately cruel. The word is also frequently used to describe light-hearted cheekiness directed at somebody in a position of authority, such as a boss or teacher.
Brian was my most difficult student. He was always asking impertinent questions in class.
I hope Anne didn’t think I was being impertinent by asking her about her private life. I was just making conversation.
Only Alex could get away with such impertinence. The boss finds him hilarious.