Goodbye or just See Ya Later?

To add insult to injury I really feel like I had to give up a friend today. Husband and I have had one friend for a few years who I think it's safe to say we are equally friends with. I think this doesn't happen very often in a marriage and it definitely has it's up and down sides. He doesn't make many friends and so despite my becoming close to this friend first I really thought it was great for him to have someone he could actually talk to.
My desire for him to be a normal human being, have friends, not totally hate interacting with humans in social settings was so strong that I was able to overlook my jealousy that this friend was a woman who would accompany him out for happy hour. I was often invited as well...and 90% of the time I successfully overcame my jealousy of this relationship. Even when he choose her over his brother to drive halfway across the country together in a UHaul. I mustered every ounce of willpower I had and turned it into understanding.
I really just wanted him to be happy.
Coincidentally this friend is finding her marriage crashing down at the same time as ours. Her response has been to flee home to family and sequester herself. I've been really supportive of this move and have only communicated with her minimally.
I found out today after e mailing to wish her a happy birthday that she has been talking with my husband. She knows "how bad my situation is" and wouldn't wish this on anyone. But is not ready to talk yet.
I think this was the last straw for me.
I don't want this next phase to be characterized by his vs. mine...I don't want to only talk to people sympathetic to "my side". I want to continue to be a well rounded person and I want both of us to continue to communicate with the people who matter. But this one case feels different.
Am I being rash? Am I going to change my mind in a few months?  Who knows...but I feel really betrayed.
I think almost all of you reading this blog know that I am not one who says goodbye to friends. We may not talk for long stretches of time but we always come back.
I think for the first time in 8 years and possibly only the third time in my life I have to say goodbye to a friend I really care about. A person I find it easy and fun to be with. Someone I can have a dance party with followed (or more wisely preceded) by a serious life's a bitch but what do we now conversation.
You'd think given my itinerant lifestyle I'd be good at goodbyes. But there really haven't been many of those, it's always more of a see ya later. My gut just tells me this one is different.

So....ya'll are to me what cuisinart is to food....get in here and help me process.