I think HB is trying to make the point that their are 2 separate journeys going on. One from the MLC'er and 1 for the LBS. Jacks point is that the LBS journey is usually way ahead of the MLC trip. So in the end you will have finished what you are doing way before your spouse. I know when my wife was going through replay so was I(begging, pleading, doing everything wrong) and when she was depressed I needed anti-depressants to relieve my stress/depression. The point becomes what HB is saying is that you need to go though your own stages and lead the MLC'er out of the tunnel. If you were to have an affair/relationship of your own both trips would stop and both of you would not survive the journey.
Also detachment is something that the LBS must learn in order for the MLC"er to be able to complete their journey.