Annabel, it's so kind of you to write that massive post as a reply. I'm really glad you've shared it on the other thread so other people can benefit, too. (Just a note from when I read your post there, Mr W and I aren't married yet, but we act like an old married couple much of the time, so you're not far off!)
I think I will take that approach. After these deliberations (and under much influence by the kind advice given on this board), we have decided to start having sex again (do you appreciate my avoidance of euphemisms, Magdlyn? hehe)
I'm a still little weary of going in with no limits at all, but I see your point. In a way, I think it's enough that we're all clear on that Sabina and I aren't planning to ever set up house together. I don't want to "lead her on" by leaving that possibility open. Anyway, I can't imagine that we would ever both want to move in together, but if it did, I suppose we could re-assess.
In any case, yes, if one day I start doodling her name in the margins my notebook, I won't be horrified.