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,我都是得来全不费工夫。但经常的情形是,我假装睡着或专注于某事或漫不经意的时候,他们那些貌似平白无误呼之欲出的隐私秘密又会变得犹抱琵琶半遮脸,羞于启齿了。
" --- 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.