万事开头难 Everything is difficult at the start
万无一失 not a single miss in a thousand times.
落井下石 to hit a person when he's down
隔墙有耳 Pitchers have ears; walls have ears.
开夜车/挑灯夜战 Burn the midnight oil.
开诚布公 He always opens his heart to his spouse when he has a problem.
盗亦有道 Dog does not eat dog.
善有善报 One kindness is the price of another.
损人利己 to enrich oneself at others expense
小Car笔记：
spouse：配偶 【例句】He never mentioned his spouse. 他从来不提自己的妻子。
enrich oneself：自肥，利己