Well, here's the denouement. They both read the email, and they've talked, and my dad called and said, "you're right." Not entirely unexpected, because I was right, but that's not really the point.
He then says, "I've got somebody here who wants to talk to you," and hands the phone to my mom. Her first words are, "I understand - I understand that I'm just not going to be able to talk about my feelings."
AAAAAAUUUUUGGGGGHHHHHH! [head explodes]. We are now entering the "poor me" phase of the next who-knows-how-long.
Anyway, she's coming up to see my aunt on the 23rd, which is a week from yesterday. At first she said that she was going to go up there, pick my aunt up, take her to look at this place where the cousins' reunion is going to be in September, take her home, drop her off and then go home, "since I don't want to interfere in your life...." [head explodes again].
Either she doesn't get that her talking about how she feels is fine as long as she respects certain boundaries about it, or her life with my dad is so miserable that the only feelings she has about her life are that my dad is making her miserable - which I don't entirely believe, BTW. My dad can be a selfish brat, but he's not intractible.
So, we'll see. I know that part of the reason she's really pissed off at me is because she didn't want to admit some of what she said about the choices she made, and I don't think she wanted my dad to know any of it, either. See, my parents had what used to be called a "shotgun" wedding back in '63 (although, technically, there was no shotgun, and my grandfather and my uncle would have just as rather my parents didn't get married, but that's another story for another day).
There were issues there that pre-dated her and my dad's courtship that my mom has just sat on for 44+ years, and she won't let go of any of it, since it seems much more useful to hold it over his head for the rest of their married lives. As I sit here now, I don't know whether my mom is mad that my dad knows things she hadn't planned to tell him, or if she's sort of glad that it's out in the open because she wanted him to know but didn't want to actually come right out and take responsibility for it. Or both.
Damn! Raising parents is hard......