Well, guys, I just don't feel your pain. I got my wife (then girlfriend) into my music before I even had a system, and now she enjoys the better sound.
While she never puts any music on herself (I have coming up on 700 CDs), she does like whatever I put on. And when I force her to sit and listen, she actually can hear the difference from the weaker stuff to the better pieces.
I guess if your spending the house payment on audio gear, the wife might have something to say, but if you're not, why hide it. You're entitled to your hobbies for Christ's sake! I wouldn't put up with having to lie to get what I want. F--- that.