Elf,
Wow, you must be a very self confident person to be able to live in such an environment and not become jelous, or feel insecure about it. Just being able to cope with the alternative living arrangements so well is a huge achievement to you as an individual person!
May i ask though, does your husband ever just spend time alone with you to make you feel special? or time alone with her, or do you and her?
I think this would be MY biggest concern in such an arrangement, i mean for me, the best times in a relationship are when you are alone, close and face to face intimate and relaxing with someone you love. Like sleeping in on a sunday and chatting and just staring at each other etc. I imagine it would be hard to do this if there are three in the bed.
I mean threesomes and all that extra fun stuff is all good but when it comes down to being in love, and having those 'couple' moments - how do you do it? and how do you cope when he is off giving her one of those moments, or vice versa?