Significant other

People here don't use boy friend or girl friend, they use significant other

It is interesting to learn something like this. Significant other is not specified. This term can refer to married or unmarried life partners. Perhaps it is because gays and lesbians are quite active here. It is common to have gay or lesbian coworkers. It might be hard for life partners to disclosure the role. So, people tend to use a common term like "significant one" in conversations.