答案：other half, better half, significant other 都可以。

　　字典上解释是： significant other --your husband, wife, partner or somebody that you have a special relationship with 配偶、情人、恋人。。。总之是和你有着非同一般的关系。

　　老外也怕麻烦，也怕得罪人，只好用个模棱两可的概念“ significant other”来泛指“另一半”。