Unfortunately you're in a tough spot, Ox, b/c your wife very likely doesn't take your stated boundaries seriously, based on your past behaviors and unwillingness to enforce boundaries. So when you say "I do not want to hear you talk about OM; we are still married," it goes in one ear and out the other and she comes back and tests you on this again and again and again.
All you can really do is enforce your boundary, and show 100% consistency in it. It's like with kids -- you can stick to your guns 19 out of 20 times, but if it's not 20 out of 20 you've pretty much blown it.
With my wife, I had a pretty good track record already of "saying what I mean and meaning what I say," so I really only had the lay the boundaries once or twice and she abided by them. With you, you have this "passive-aggressive" history with your wife, and some dysfunction there, so it's going to take a longer stretch of being consistent I think.
