“对人不理不睬”英语里我们可以这么说：

give someone a cold shoulder，例如：I thought that Wendy and I were friends, but lately I've been getting the cold shoulder. 我以为我和温蒂是朋友，但是最近我总是被她无视/她对我不理不睬的。You‍ cold ‍shoulder.‍ 你对人家都不理不睬

Good. Thank you.