Well not for nothin' but this is my observation and mine alone. I have not been bribed, or threatened or drugged to say this.
I know that I've said this to you before, but people want what they can't have. Your wife seems to react to you in a positive way when you seem to be detached. I saw this same movement and my counselor explained it to me saying that if there were a circle we would be standing in the middle while our WA's are way over against the farthest edge (represents them trying to get away from the marriage). When we change what we were doing in trying to win them back, it forces them to move back towards the middle to see what's going on. The dynamic changed from what it once was. If they don't like it, like children, the confusion causes them to test the water, or in your case, your wife's having to make the connection in order to see if you are still 'there'.
Now you find out that she's aiming herself at this unattainable relationship with a rocker. Well she can't have him but if forces her to go after it. All the while, she has 1 toe in the pool of La_Esp in order to make sure that you're still there.
Maybe you should stay somewhat detached in order to force her to put her feet in. You do know that this could go on like this for a very long time unless you help her along. How do you know that she won't keep someone in the background (if only in her mind) as long as she knows that you will always be there? If that's enough for you that's fine. I would just think that after a certain period this would be an unhealthy way to live for both of you, and oh so unrewarding!