Hairy, Sorry the talk went so poorly. I agree that GS would have been ashamed at her, she was acting nutz!
All I can say is chalk this up to a learning experience. From now on, you know that you can never be nonconfrontational with her. Obviously she likes confrontation and was trying to bait you into a huge one, eh.
My take is that she absolutely knew what the convo was to be about--after all, she is the one who brought it up. But as I said before I think her motivation in bringing it up was not to talk about it and find a resolution but to get some reassurance that you were there for the long haul, despite her shortcomings.
When that was not forthcoming AND you had the nerve to ask for more, she blew.
And, hey, I know all about this tactic. You blow up and totally lose it and then the guy is consumed with rectifying your mood--the focus is completely off of what you were supposed to be talking about and it will not rest again there for some time.
I don't know where your mood lies this morning but I would be tempted to send another email (what's she gonna do--cut you off??!? ha ha ha ha ha) that says, I'm sorry I wasn't clearer on what it was that I intended to talk to you about. I thought it was clear since it was the morning after you asked me if I had a girlfriend. I wanted to talk about the lack of sex in our lives and what we can do about it. At the same time, I wanted to know what would make you feel closer to me. Do you think we can have this conversation sometime soon?