I'm happy to share my experience. This will bring you up to speed in a nutshell: I was in very long term marriage and had tinkered with opening it up. So when it ended I was philosophically open to polyamory when I met my poly partner. I thought I'd be OK with it but as my love for him grew my anxiety about it grew and my desire to have anyone else disappeared.
Just like your lover's wife will have to do I had to work through it. Most of that work was done between my partner and I. I can honestly say that i have never really blamed his SO. I have had issues with the way she has handled herself at times but that is a whole other story. I have told her how I felt when I've had a problem, nicely of course, and she's always respected it when I've asked for certain boundaries. We are at the stage where I am now actively trying to build a relationship with her, and having some success. As the partner in the V I would rather be more of a triad, I just think it would work better all round and it's what my partner wants. That's one of the reasons why I consider myself a polyamorous mono (at this stage). It's taken me two years to get to this point I might add.
I can see where your lover's wife has found your relationship a bit hard. You can "academically" accept something but you never know how it can throw you until it actually happens. I can see how the intensity of your relationship may have pushed her. But she signed on for it. At this stage anyway I don't think you should be worrying about it.
Oh and I've learned the hard way about telling other people. I wouldn't tell anyone until you are very sure of yourself, or they were polyamorous. Other people just reflect back to you your own anxieties which is useless to you. I started moving ahead in leaps and bounds when I started looking for the positives in my situation. If your friend can't/won't respect your relationship you may have to pull back from her for a while. At the very least don't vent to her, don't discuss your relationship with her and ask her just to respect your decision. I have had to do that with my daughter who thinks I'm "abnormal" and it seems to be working.
Good talking with you
Last edited by sage; 07-09-2010 at 10:06 AM.