The dream is total fusion, two people folding down into a single unit. In practice it is a negotiated blur, each of you agreeing to overlook the other's edges in exchange for the same courtesy. Sweet, load-bearing, and quietly built on a great deal left unsaid.
The edges do not actually disappear; they just get politely ignored. For a while the shared mythology holds everything together, until one of you remembers being a separate person with separate wants, and the blur has to be renegotiated.
The music carries that ambivalence, warmth shot through with a knowing chill. Two lines that almost lock into one, a harmony that is lovely and very slightly off, closeness with a hairline of distance running through it.
Here the honeymoon curdles into doubt about the whole premise of union. Play it when you are close enough to someone to wonder where you end and they begin.