impertinent

/ɪmˈpɝː.t̬ən.ənt/
rude and not showing respect for sb who is older or more important 粗鲁无礼的；不敬的 SYN impolite
an impertinent question/child
没有礼貌的提问／孩子
Would it be impertinent to ask why you’re leaving?
问一下你为什么要离开不知是否唐突？