" Because deep in her heart, she wanted him for herself.
But that was selfish, and Kate had spent her life trying to be unselfish, and she knew she could never ask Edwina not to marry Anthony for such a reason. If Edwina knew that Kate was even the tiniest bit infatuated with the viscount, she would put an end to his courtship at once. And what purpose would that serve? Anthony would just find some other beautiful, eligible woman to pursue. There were plenty to choose from in London.
It wasn’t as if he were going to ask her instead, so what would she have to gain by preventing a match between him and Edwina? "

― Julia Quinn , The Viscount Who Loved Me (Bridgertons, #2)