Lady Marmalade said:How low have we sunk in values and sanctity when we view this all as normal, acceptable, rational behavior.......
Well, in the past the nobility and royals had to marry for reasons other than personal ones, and it was accepted that after heirs had been produced incompatible couples could find their emotional fulfillment elsewhere. As this sort of requirement was ending and marriages were being made more for love, so that it shouldn't have been necessary to find one's soulmate somewhere other than in one's spouse, the permissive society happened along and promiscuity became more the norm anyway.
I found it interesting that the Queen Mother, as Duchess of York, was friendly with Lady Furness when she was the Prince of Wales's mistress; her aversion to Wallis seemed to be that Wallis was ambitious and indiscreet, not that she was a married woman who was the Prince's mistress.