They are clearly very much in love. It must be the end of a series of nightmare years for Camilla, every day reading in the papers about being the mistress this and that. They are entitled to have their own happiness the same as everyone else.
Writing ... it begins as an amusement, then it becomes a mistress, then a master, and finally a tyrant.
No lover ever studied every whim of his mistress as I did those of President Roosevelt.