Her 100% Loyalty Was a Lie

From the back cover

A man can see a loyalty score floating above every person's head, and anyone whose score falls below sixty percent will eventually leave. He watched his mother's score collapse the day she cheated and his brother's drop the day he ran away, so he learned to walk away from love before it could hurt him. Then he met Natalie Farr, whose score for him held at a perfect hundred for ten years of dating and marriage.

On their son Leo's third birthday, Natalie breaks her promise to be home and returns late, smelling faintly of cigarette smoke. The score above her head has fallen to eighty-eight. The next day, at her office, he finds her leaning over a young new assistant, Zachary Bennett, and her score slips further. She hands his homemade lunch to the young man without a thought for whether her husband has eaten.

He quietly begins planning his exit, even as Natalie fusses over him through a night of illness. How far her score will fall, and what he will do when it does, remains to be seen.