Latest language gaffe/near miss with humiliation

As an intern, anywhere really, one is constantly anxious about how to slip into the social scene at the office/company. If you have an intern, know that he/she is over thinking every action so as to avoid being both completely overlooked or in the spotlight. This internal tension (no pun intended) increases when the job lands the intern squarely in a foreign culture where he/she cannot even rely on gut social instincts. While I am constantly strategizing about how to ease into the social scene here, I am never actually confident about how my actions are being interpreted. With such deliberation to say and do just the right thing, you can imagine what affect one major gaffe might have on my psyche.

While my Chinese vocabulary continues to grow, I am still very capable of making grave and humiliating mistakes. I had a close call during a series of email exchanges with a PhD student here at the institute. We bumped into each other outside the institute and he invited me to the public oral defense session of his thesis. There is a specific word for oral defense of one's thesis, "da bian" (答辩) which was new to me when he spoke it. I attended the session and managed to comprehend only the gist and not a single detail of his extremely technical presentation. Afterward I confidently typed up an e-mail thanking him for including me and asked him how he thought his "da bian" had gone.

However, due to my dearth of Chinese character recognition, I used the characters "大便," which is also pronounced "da bian" but with slightly different tones and unfortunately means..well... excrement (to put it gently)! I was one mouse click away from thanking him for inviting me to his defecating session and asking him how he felt about it had gone.

I swear Chinese is a code not a language!