I'm coming back to give a sort of "this is how it went" summary, but first, I'd like to thank all of you for reading and commenting. I have at least one PM to answer still...
Yesterday got pretty tense as my email hit their inboxes. They both reacted about how I expected each to react and some hurtful words were said which changed the landscape of the entire dialogue.
However, through that, I learned there *was* an underlying problem and we (eventually) managed to talk about it. As is true of "the big fights", it's an on-going thing we're all going to have to work on. But now that I know the problem is there, I can.
In the end, we got to the make-up sex *blush* and it was everything I've been needing and more. So, while I would have liked to skip the yelling and the cold silences, what I'm left with is much reassurance that things weren't imagined *and* the reason for them wasn't a desire to break the triad into a vee (which was my fear).
Thank you all, again. I hope one day to return the favor to someone here on the forum.