to cut a long story short中文含义就是，“长话短说，简而言之，挑重点地说”。

【例句】
I spoke to the boss and to cut a long story short, I’m getting a promotion!
我找老板谈过了，长话短说，我晋升了！

The details are boring, that’s why my long story is short.
细节很无聊，这就是我长话短说的原因。