He called it " a sore subject, " or something he didn't feel happy about.

他称之为“一个令人不快的话题”，即令他感到不高兴的事情。

Birthdays aren't usually a sore subject, that's all.

生日通常不是什么痛苦的话题 是吧。

I'm sorry, it's just kind of a sore subject.

不好意思 这个话题让我心情很不好。

Bolla was a sore subject with him; there had been a rivalry between them about some work which the committee of Young Italy had finally intrusted to Bolla, declaring Arthur too young and inexperienced.

博拉对他来说是个棘手的话题。他们之间曾因为青年意大利委员会最终委托给波拉的某项工作而发生争执，他们宣称亚瑟太年轻且缺乏经验。