I've been cheating on my married boyfriend of 6 years with my now-husband of 4 months for the past 3 years
What are you trying to accomplish with a complicated relationship?
My boyfriend will never find out about my affair
Wow, you are in way over your head and you should just step away from everyone right now. Cheating is never forgivable and no one deserves to get their feelings betrayed hard like this.
My husband and I got married without him knowing that I have a boyfriend at all. I don't think they'll ever find out about each other.
Obviously you know this cheating and scheming is wrong, so you should try to stop covering it up and end it with the boyfriend. It will eventually come out and when it does, the surge of emotions from everyone will be too much to handle.