ADJ-GRADED (不分场合)乱开玩笑的,贫嘴的 If you say that someone is being facetious, you are criticizing them because they are making humorous remarks or saying things that they do not mean in a situation where they ought to be serious. (不分场合)乱开玩笑的,贫嘴的 [disapproval]
The woman eyed him coldly. 'Don't be facetious,' she said.