
It depends on the relationship, as with any label its up to the people in the relationship to decide if it fits. For my partner and I, it’s about commitment. We’ve lived together for four years, we tend to live together for the rest of our lives. We make financial decisions together. We provide each other with long term companionship and love. Other than sex/romance, we act the same way a married couple would.
I mainly use the label because “my roommate/best friend” just didn’t feel like an adequate description our relationship. My partner is important to me. Our relationship is one of the most important thing in my life. I wanted a specific label that conveyed how this relationship was different than my other friendships.