Let your heart rule your head 情感战胜了理智,感情用事 act according to what you feel rather than what you think is sensible
Don't let your heart rule your head. I know you like him but are you sure you can really trust him? 不要感情用事.我知道你喜欢他,可是你能确定自己真的信任他吗?
Let the genie out of the bottle: 把妖怪放出瓶子,引发灾难性后果 do sth that causes a big and permanent change in perople's lives, especially one which might make a situation worse
Once you make carrying guns legal, you let the genie out of the bottle. 一旦拥有枪支被合法化,后果将不堪设想.
