1. I think it is very normal for you to feel this way.
2. I really admire you for having made this offer to your husband (though I'm sure some will disagree). I've always maintained that I would do the same thing if I were with a guy who wanted/needed a lot of sex and I wasn't willing or able to provide it.
3. If he has sex outside the marriage with your blessing, it isn't "cheating."
4. Of course there's a risk that some of his emotions will be diverted to the other woman. On the other hand, the risk of him having no means of satisfactory sexual expression is greater still.
I have to tell you that your courage, generosity and love have brought tears to my eyes. If you honestly, calmly, bravely and lovingly tell your husband of your most recent feelings, it might open up a whole new channel of communication and love. It might help him communicate his feelings, help him slow down a little and help you trust him more. It might also open up the door to find a way to make sure this event seals the bonds tighter between the two of you instead of tearing you apart. I think you'll find a way.
Hopefully Miranda will chip in, as someone who has negotiated an open arrangement.
When you see it coming, duck!
I don't know what physical
constraints you have, normally you still be able to respond physically,
but it sounds like this is a mental response (possibly a result of
grieving for the effects of the illnes).
...me too...I have to wonder if she is "game" to enthusiastically engage in his sexual satisfaction...I mean, I understand if he has said "no, if you aren't horny, I don't want you" there is little she can do...if her ability to use her hands and lips along with her genitles have been lost, then I can see that she is left with little else but to 1) ask him to give up partnered sex or 2) agree that he seek partnered sexual satisfaction outside of the marriage...I absolutley think I would be just as hesitant and scared as she is...my husband connects sex and love...it would be next to impossible for him to not fall in love with (the romantic, fluttery love kind of love) with someone that he became sexually involved with and that would effect his romantic, fluttery kind of love that he feels for me...what a hard place to be in...hopefully, there is something the two of them can still do as a couple to work toward his partnered sexual satisfaction together...but, if not..hopefully she will come to a place of peace about the situation...