Well, we're kinda getting away from "general & theoretical" into something that should be more in the Relationships Corner, but here goes:
AnnabelMore: Thing is, they're at that level of friendship and emotional commitment already, and it doesn't phase me, and they're both fairly committed to maintaining the friendship even if this new thing (romance? flirtation? Neither of them is really clear on that) gets off the ground and then crashes. I'm fine with all that. Wifey IS already thinking about Jane Doe's next Christmas presents, but she does the same thing for anyone she cares about that much, myself and our kids' godparents included, and that isn't a sexual or romantic thing in my wife's world. If for some reason I got terrified or something went wrong and I asked to end the openness, that would close the door on one small part of their relationship (potentially a bigger part in the future, I know, but not the biggest part by any means). In any case, I don't see that happening; I was just relating how much we've talked about all this, and how we've tried to address some of the issues that have arisen.
Galagirl: See above. They have talked about it. Not a ton, as Jane Doe has been busy, in and out of town, and they seem to have some difficulty communicating at times around these issues, but they're both committed to each others' well-being and want their friendship to be a lifelong one, whatever happens with this new, potential, and undefined aspect of their relationship. Thanks for the links, and thanks for the language of "the Bus." We've already used that language a few times in the long talk we had last night after I read your post. "So what about (such&such fear)? What if THAT bus hits?" Useful to have a shorthand phrase like that.
Yeah, there are certainly no guarantees in life. I initiated this thread to get an idea of the breadth of lifestyles and possibilities that we might fall into. The terminology is still new, the ideas foreign, I just needed to learn more about what's out there for us.
One more for Galagirl: Would you mind defining "closed polyship of two" for me?