Which begs the question that I've always wondered - what exactly is that imperceptable shift? I've seen it in my scenario, but not understood it.

Is it because the GALing brings out the best in a person, makes them attractive? Is it because the WAS needs control, and leaving gives that to them, and the loss of your fear gives you back that control? Is it because they WANT you to take control? Some combination?

Why would Mrs. SP nonchalantly trivialize her marriage with another man, and the only thing to reverse her ride-into-the-horizon is Mr. SP doing the same thing?

Because of his dalliances with Miss Someone, SP has so eloquently pointed out his understanding of how Mrs. SP could be swayed to sample the oh so tender grass on the other side of the fence.

Mayhap the explanation is a rather poignant twist of fate - that Mrs. SP has seen and perhaps now understands how Mr. SP feels having been put into his position, and not liking a bit to be on the receiving end of knowing your spouse is canoodling about.

Maybe it IS all about the shoe being on the other foot? Maybe I can't simply lump all scenarios into one tidy, explanatory box?