Sometimes we say things without thinking. Very often a thoughtless remark may hurt others' feelings or cause a misunderstanding or an embarrassment. We must, therefore, always think before we speak.

Once I told an old friend how beautiful his girlfriend looked when I saw them together at a movie theater the other day. Unfortunately, I made a mistake. It happened that she wasn't with my friend. She was with someone else. I had let the cat out of the bag, so to speak. I'd never been so embarrassed in my life. I certainly learned my lesson, but at a very high price. His girlfriend never spoke to me again! And to make matters worse, it is rumored that they eventually broke up.

halfway  adv.在中途   Do not give up halfway.       persistent 持久的
look before you leap 三思而后行
Anyone likes Sam, because he is so thoughtful of others.
make a remark     make a statement (正式)
the other day  最近几天前的一天    cinema (文诌)
error = mistake n.      mistake A for B 误将A当B
It happened that... = It turns out that .... 原来是
let the cat out of bag = reveal the secret  泄露秘密
Bruce is a scholar, so to speak. 可以这么说
learn one's lesson 学了教训
cheat on sb 对...不忠