The Devil You Know by Freida McFadden

Dr. Jane McGill is in heaven.
She’s got a great job at a VA Hospital, an adorable daughter, and a loving husband. Granted, it would be wonderful if her preschooler wouldn’t wake her up at three in the morning, and it would be a miracle if her husband would change the toilet paper roll once every millennium. Still, in most ways, she has the ideal life she’d always imagined.
Then Jane discovers that Dr. Ryan Reilly is the VA’s newest vascular surgeon. Dr. Ryan Reilly, a.k.a. Sexy Surgeon, a.k.a. the biggest jerk she ever loved.
A decade ago, Jane broke up with the Sexy Surgeon to marry the Nice Software Engineer, but as cracks and crevices appear in her marriage, she can’t help but wonder what life would have been like if she’d made a different choice. Or if it isn’t too late to change her mind…