冤家对头 sworn enemies
Explanation
指关系长期不好，经常冲突的双方。
Refers to two parties with a long-term bad relationship and frequent conflicts.
Origin Story
从前，在一个小山村里，住着两户人家，分别是张家和李家。两家世代居住在此，因为一些琐碎的土地纠纷，两家积怨已深，成了不共戴天的冤家对头。张家以务农为生，家境殷实；李家则以打猎为生，性格粗犷。两家平日里互不相往来，见面就如同仇人一般，剑拔弩张。 有一天，村里发生了一件怪事，村里的井突然干涸了。全村人都面临着缺水的困境，村民们开始四处寻找水源。张家和李家虽然是冤家对头，但面对共同的危机，他们不得不放下成见，互相合作。张家出人出力，翻山越岭寻找水源；李家凭借对山林的熟悉，带领村民们寻找隐蔽的地下水脉。 经过几天的努力，他们终于找到了一处清澈的山泉。全村人终于解决了缺水问题，张家和李家也因为这次合作化解了多年的恩怨，从此成为了一对好邻居。他们意识到，在共同的利益面前，放下成见，互相帮助才是最重要的。
Once upon a time, in a small mountain village, lived two families, the Zhang family and the Li family. The two families had lived there for generations. Due to some petty land disputes, the two families harbored deep grudges against each other and became sworn enemies. The Zhang family made their living from farming and were well-off; the Li family, on the other hand, hunted for a living and had a rough personality. On a daily basis, the two families did not interact with each other, and when they met, they behaved like enemies, ready to draw swords at each other. One day, something strange happened in the village: the village well suddenly dried up. The whole village faced the plight of water shortage, and the villagers started looking for water sources everywhere. Although the Zhang family and the Li family were sworn enemies, in the face of the common crisis, they had to put aside their prejudice and cooperate with each other. The Zhang family contributed manpower and resources to search for water sources across mountains and ridges; the Li family, relying on their familiarity with the mountains and forests, led the villagers to search for hidden underground water veins. After several days of effort, they finally found a clear mountain spring. The whole village finally solved the water problem, and the Zhang family and the Li family also resolved their long-standing grievances because of this cooperation and became good neighbors. They realized that in the face of common interests, putting aside prejudice and helping each other is the most important thing.
Usage
用来指长期积怨，经常冲突的双方。
Used to refer to two parties that have long-standing grudges and frequent conflicts.
Examples
-
那两家是冤家对头，世代为仇。
nà liǎng jiā shì yuānjiā duìtóu, shìdài wèi chóu
Those two families are sworn enemies, generations of hatred.
-
他们俩是冤家对头，总是吵架。
tāmen liǎ shì yuānjiā duìtóu, zǒngshì chǎojià
Those two are sworn enemies, always fighting.