As to your original post in this thread, I was going to respond to your questions:
Am I being utterly unfair in this? Does this make me a terrible person?
No, of course, you're not a terrible person and, by virtue of the fact that you even ask that, obviously you have compassion and are wrestling with these issues. You seem to have a good amount of awareness about your issues/motives for not wanting him to love anyone else nor be sexual with anyone else. It's only unfair if one person dictated what the other should do without asking for input and considering what they want. Fair doesn't always mean equal, and relationships shouldn't be tit-for-tat (IMHO). However, I do suggest you keep asking yourself why your stomach gets into knots, play out some imaginary "what if" scenarios in your head and really pinpoint the things that make you most uncomfortable. More self-knowledge is never a bad thing. And keep talking talking talking.
BTW, River is one of the most well-intentioned, compassionate, spirit-focused, good, good people who post here and I don't think he has a rude bone in his body. You quite misread and misinterpreted what he wrote. I mean, hey, you can't unring a bell - all he was saying is that you've started on a road of questioning the parameters of your marriage, and doing so has altered how you look at each other, the contract of marriage in general, and what choices are available to you. Possibilities have expanded, your knowledge of each other deepened, your communication skills challenged, and so on, and it would be hard not to keep seeking new ways to enhance and nurture your relationship with your DH, no matter what those paths could be - including remaining monogamous if you so wanted. So chill - he was not rude by any means.