Our wedding party will of course bring their significant others or have the option to bring a plus 1. But for some of our regular guests, there are a few who might be in relationships, but we don't know the other person either at all or even know if they if they still are in a relationship. For example, one friend doesn't have facebook, and hardly responds to texts in order to figure this out. Trying to keep the wedding small, we would rather not invite those significant others of regular guests since we literally have never met them. Knowing etiquette may say otherwise, just wondering what you gals think.