Darker Shade of Pale Series by Mandi Rei Serra

Despite her once-happy marriage to a wealthy and brilliant scientist, Selesta Haytham needs to escape. Christos and his peculiar sexual tastes have taken their toll on her psyche. Besides, he's married more to his work than he is to her -- and that work of his is going to be the ruin of mankind. Desperate to have any measure of freedom, she fakes her death, only to fall in with a lonesome stranger who has made it his life's mission to avoid civilization and all temptation -- including her.