仇人相见，分外眼睁

Explanation: Means that when the two sides meet, when hostile to each other on the other side are especially alert and sensitive. 　　Source: "Awaken the common saying Cairui Hong insults and revenge": "Dear husband, is seen in a very reasonable; only enemy of each other, exceptionally Yan Zheng, ru better than the past few days!" 　　Examples: Song Jiang looked at the heart of a hi angry: Hi Lo staff who were outside the meritorious deeds, anger hate Shiwen Gong Chao shot King, ~. ★ "Water Margin" Sixth Eight Back