I can see your point about him telling your mutual friends about your diagnosis. that would just piss me off if my wife did that, and I would be left with feeling responsible to explain myself to whoever she told. Not to mention the other people that they will tell. I would have to assume that sooner or later word would get around to everyone.

I can see myself getting standoffish with the mutual friends. That's prolly not the best way to go. I think the best advice is to continue on like normal, like nothing has changed and if any of them want to change the dynamic of your friendship because of the news, then they can just screw off. You never know, You might be backed by most of them. They might even be questioning your husband as to why he told them! Telling him that it's not his place and stuff. Doubt your hubby would share that part of the story lol.

It really does sound like he is using your diagnosis and emotional fling, if that's even what it was, as a means to do whatever he wants. I hope that ends soon, and he realizes that it's not about keeping score, but about two people doing the best that they can with what they have to live together and be there for one another.