Bah, I think its actually healthier for you to just tune out and go inward rather than try to have compersion. Protect yourself first. Leave them to their own devises.
It's interesting you say that, about tuning out. I kind of feel that's what I have been doing, and it's allowing me greater acceptance, or giving me peace with it all, which, oddly, is allowing me to feel closer to my wife. Our communication has certainly improved (as has our sex life).
Have you confronted him at all on this? I would of blown up by now and would of told him either he tells his wife or you do.
I haven't confronted him yet. I'm sure the day will come when I do. I try to think before I act. His interworkings of his marriage are still pretty unknown to me. It's obvious that he and his wife love each other, I just don't see the "In Love" when I look at them. Of course that's the outside looking in. I have spent a few evenings with them both, and I really do like her. Thing is, Im a product of a very ugly divorce, and I believe if he and his wife are going to ever get their shit together, it needs to be of their own accord.
I know it's like being on a train without a complete set of tracks. I know this will end poorly for them, I just need to protect myself, and do my best to be there for her when it goes amuck.
It almost seems like she's kind of just finding herself. We've had discussions about 3somes; swinging, she's just really out to explore and find herself. I've been around the block a few more (quite a few more) times than she. She's lived a pretty vanilla life, and I don't know what's caused the sudden need to explore for her, but Im no shrink either.
If I blow, it'll just be a mess, if I keep my cool, take care of myself and protect her, it will in turn help all involved, I think. It's not like I ever thought she was a pure as the driven snow, hell our first night together was a 3way. My concerns aren't in the immediate, as long as I can stay calm, I can do that, it's the long term that worries me. It's the 5+ years down the road that scare me to no end.