I've been looking through the forums, and it's really good when I find something relevant, and then I go through the WHOLE thread. I figure I should keep updating this little intro thread in case somebody having metamour problems in the future and find it relevant.
I found this:
The TL;DR version is that the author, after a particularly bad experience, learns that having direct communication to metamours is completely essential to her relationships. Made a lot of sense to me.