This has to be up there with some of the most fun Chinese sayings – it stands out in a sentence, and will cause some puzzled reactions if you use it among people who’ve never heard it.
While the literal translation of this saying is to “to expose a horse’s leg”, the 馬（马 mǎ）used in this saying doesn’t actually have anything to do with horses. There’s an interesting story that accompanies this saying and although it differs very slightly from source to source, the main points are the same – Due to the wife (surnamed 马, so that’s where the ‘horse’ comes from) of Ming dynasty emperor Hongwu having unsightly legs, she was reluctant to show them off and had extra long dresses made to cover them up and keep them hidden. Then one day while she was out in the city a big gust of wind blew her dress up exposing her legs – and so the saying goes… to expose a 马 leg came to mean to accidentally expose a secret.
Now that we know the meaning, and the back story, let’s see some usage examples.
note: After some good discussion on Google+ over the uses of 漏 and 露 together with the fact that 露出馬腳 is a 成語, I’ve changed the definition above from 漏了馬腳 to 露出馬腳, though the meanings still remain exactly the same.
Obviously there’s the basic:
你漏了馬腳！（nǐ lòu le mǎ jiǎo）
You’ve let the cat out of the bag!
You’ll also see this saying quite often in news stories, usually relating to business, since trade-secrets or product release information is often accidentally released:
yáoyán zàiqǐ! zhēngrén xùnxí lòumǎjiǎo, 8 yuè tuīchū xīn iPhone?
More Rumours! Job ad lets the cat out of the bag, new iphone in August?
Here’s a fun example from some cheating exam students:
kǎoshēng kǎoshì pín hē shuǐ lòumǎjiǎo kǎoguān fāxiàn píng zhōng cáng dáàn
The exam students repeatedly drinking water gave them away, the examiner discovered the answers were hidden inside the bottles
Now go and have some fun using this phrase and if you have any secrets to tell use the comments to 漏馬腳！
A commenter on Google+, 成默予, just pointed out that another common way to say this phrase is 露出馬腳（露出马脚 lòu chū mǎ jiǎo）. This is a very interesting point, since 露 and 漏 in this sense （洩露 and 洩漏） are essentially synonyms. It could be a regional thing with China using 漏 and Taiwan using 露 – but either way this is a lucky case as not only are the words synonyms, but they have exactly the same pronunciation. So no matter which you favour （露 or 漏） it won’t make any difference when speaking 🙂
I’d love to hear more input from native speakers from difference parts of the Mandarin speaking world!
Jacob also points out below that 露出馬腳 is an idiom, while 漏馬腳 is just a saying, which explains why it can be modified.