SD - you really can't eat your cake and have it. If OW is truly on your mind, then it may be time to call it quits with W. It does no good to play "what if" games in your head, and if you WERE to take real action ref OW, then I think you're really admitting to yourself that the M is not working, and isn't likely to work. You can't "take a holiday" from the R without destroying it. The strengh and power of our position comes SOLELY from our committment that we will work on the R until we come to the realization that it is time to move on, and then move on we shall. Without that, we're in a weak position indeed. You really DON'T want to give W anything she can hold over your head - trust me on this one.
One thing I've been thinking is that W's attitude towards sex is one of the biggest barriers. This may be true of your W's as well as mine. She has all kinds of "rules" about what is "right" and "wrong" in regards to LM. Lots of hangups. With all of that, how much "fun" and "love" can be expressed that way, when you have to watch out you don't "cross a line" and actually enjoy something on the "forbidden" list. LM involves being open and vulnerable, and being able to totally trust the other person. I just wonder how much this kind of thing plays into the whole LD thing...