Obviously it is clear to everyone that this song is about Mark and Kitty, therefore private or "self-indulgent"? I can't see any personal key or touch in it, I mean personal touch from his very own life - it is just general valid stuff about missing the beloved one etc.. so it is a romantic thing. For example, in Silver Eagle and Taormina the Dylan thing is pretty obvious, whereas this could be any other couple. In fact, it could also be a gay male couple ("brother")
About the other thing cooking here, I wish we would not start to get angry about a love song. I don't know what happened on Facebook, but I witnessed a very tough emotional day following the news today and it is really not worth it fighting about Mark in times when he should be happy about a new album.
Especially as two of the very well-known, reputated and personal friends (of mine) start to get angry!
LE