大杀风景 — “To spoil a pleasant atmosphere or one's enjoyment”

The idiom "大杀风景" (dà shā fēng jǐng) originates from the Tang Dynasty. Li Shangyin, a talented poet of that era, often used his poems to expose and criticize the dark realities and official corruption of his time.

In his collection of miscellaneous writings titled "Zazuan" (杂纂), he listed several things he considered "大煞风景" (dà shā fēng jǐng), which means 'greatly spoiling the scenery' or 'spoiling the mood'. Examples he cited included "washing feet in clear springs, drying underwear on flowers, building a house with its back to a mountain, burning a qin (a stringed instrument) to cook a crane, sipping tea directly facing flowers (instead of appreciating them), and shouting commands under pine trees."

These actions were considered by people at the time to be mood-killing or destructive to the beauty of a scene, hence the idiom came to generalize anything that spoils one's enthusiasm or a pleasant situation.