Stop being facetious; this is serious.

别乱开玩笑，这是个严肃的事。

《牛津词典》

The woman eyed him coldly. "Don't be facetious," she said.

那妇人冷冷地看了他一眼。“别那么轻浮，”她说道。

《柯林斯英汉双解大词典》

Okay, so maybe we’re not as lazy I claim, and perhaps my nostalgia for a time I never lived is a little facetious.

好吧，或许我们不像我所说的那样懒散，或许我对自己从没经历过的事情进行怀旧有那么一点滑稽可笑。

youdao

As both a long-time resident of the Harvard Square area of Cambridge, Massachusetts, and a 1967 graduate of Harvard Law School, this has been my semi-facetious but all-too-true mantra criticizing the sorry state of free speech and free thought at Harvard.

FORBES: Campus Censorship Breeds Societal Dysfunction

On hearing of the closure of his local airport, the 27-year-old had sent out a facetious tweet to his 600 followers that mentioned "blowing the airport sky high!"

ENGADGET: Man acquitted as #TwitterJokeTrial appeal ends in victory