Other Men's Wives

Under this heading, "Other Men's Wives," there are things, albeit different kinds of things, to be said about (guess who):

Ian Fleming's James Bond;
Stieg Larsson's Mikael Blomkvist;
Dornford Yates' Jonathan Mansel;
Poul Anderson's Manse Everard and Dominic Flandry.

There are others, of course, e.g.:

Rudolf Rassendyl in Anthony Hope's The Prisoner Of Zenda and Rupert Of Hentzau, two novels that influenced Yates;

Otis Vanbrugh in PC Wren's Beau Ideal.

However, I have not reread Hope or Wren recently.

There is a remarkable parallelism between Mansel and Flandry. In both cases: 

villain abducts heroine;
hero rescues heroine;
hero and heroine enjoy time together but avoid adultery;
heroine returns to her husband.

- and between Everard and Vanbrugh:

heroine's husband disappears;
she asks hero to find him;
he succeeds.