I have been reading through this, and wondering, how would I have reacted if my husband had pre-planned to get a blowjob from a male in my livingroom, in front of me. All the while thinking that maybe both wives would join in.
I can tell you that without a doubt, he would be gone. Out the door.
I sense an accumulation of deceiptful actions on his part. His secret identity (I don't believe the male to male thing hasn't happened before), his excessive use of porn, gay or not, this was not discussed as being a concern to you, and last but not least, the alcohol, which dulls both ends between reality and fantasy.
My experience with alcoholics is that often the alcohol either fuels the behaviour/experiences they want, or it dulls the pain of being unhappy when they don't get it. It could be paired with anything that is risk taking such as unprotected sex, gambling, porn. The yin and the yang of it is always in flux, because to come clean about the confusion and behaviour could mean also taking the risk of losing your partner, job etc. To keep it a secret, and live a shadow life, and a real life, at least provides for some order of balance, and a way to have needs met.
It gets a bit tricky. But essentially what I'm saying is, that when he drinks to excess, there is a reason. And the reason is often a behaviour either past or present that he is not dealing with. Stopping the drinking is only one part of healing. The hardest part in my opinion, is figuring out who you are, who you want to be, where your life is going to go because of the decisions you make, and finally accepting the consequences, which will be good, and bad.
I look at your husband, and I truly feel sorry for him. That he has led this life of deceipt and denial, not only to you, but himself, has taken its' toll. He does not realize, or care to confront the issues surrounding his behaviour (refusing counselling), because facing the truth, the cold, sober truth, is far more difficult than just making false promises, and trying to change on his own. Not only does he deny his problems, he denies that he needs help- most likely out of fear.
I'm sorry this response is so long, just a few more things to say.
For your own sake, you need to know the man you married. Until the couch incident, you didn't. For any of this to make sense to you, he must seek counselling, and figure himself out, before you can gain any real insight.
When he wants to talk and/or communicate, tell him that you will talk about the issues, only in counselling. Push that envelope a little bit. I know you love him, and excercising a bit of tough love now, will ultimately help him.
You are a braver woman than I am. As I said, I would have booted his butt out the door the minute I realized what was going on on my couch.
But, maybe we would have reached the same conclusion eventually.
I do not see this as a gay issue, or a straight issue, or a bi issue.
What has really happened is the male you married, has kept his true identity hidden, and has lived a lie. Perhaps now that things are starting to come out, the plus side of this will be two stronger people in the end.