Most of the confidences were unsought—frequently I have feigned sleep, preoccupation, or a hostile levity when I realized by some unmistakable sign that an intimate revelation was quivering on the horizon—for the intimate revelations of young men or at least the terms in which they express them are usually plagiaristic and marred by obvious suppressions.
有很多秘密，我都是得來全不費工夫。但經常的情形是，我假裝睡著或專注於某事或漫不經意的時候，他們那些貌似平白無誤呼之欲出的隱私秘密又會變得猶抱琵琶半遮臉，羞於啟齒了。
" --- for the intimate revelations of young men or at least the terms in which they express them are usually plagiaristic and marred by obvious suppressions. "
Let me break it down for you, so your translation will contain following meaning:
1, The intimate revelations of young men are usually plagiaristic;
2, (If their intentions are true, then) at least the terms in which they express them are usually plagiaristic;
3, (Not only the terms they are using are plagiaristic, but they are) marred by obvious suppressions.
You may have to use more words to express all these in Chinese.
