I believe that in many cases the chemical fog starts to dissolve as the A relationship goes on. The WAS sees the long term practicalities rear their ugly head and starts to slowly realise things won't work when they try to put it all together. Then if the M issues that caused the A can be seen to have resolved themselves, actually returning to the M becomes the easier option.
I find in my work with horses, it is best to try and find ways to make what YOU want appear to be the easiest route for the animal. It's not always easy working out how to make that happen, but once you do it normally works. Does that make sense?
Saffie me 46 H 46 M in 1986 D20,D18,S16,D13 H's A 01/05 to 07/06 H recommitted to M 07/06 renewed vows 09/06 Going from strength to strength