Just bumped into a couple sites for bisexual married guys on a blog I follow. I don't believe I've seen them mentioned here so I thought I'd pass them around.
Bi Married Men of America has some kind of e-mail list for bi married guys. I just signed up for it so don't know just what goes on there yet.
This Husbands Out To Their Wives site also has a discussion list. I just applied for membership on their list.
The guy also also said there's a HOW (Husbands Out to their Wives) Yahoo Group. I'll have to look for that one.