Undiagnosed Love by Jacqueline Lee

What happens when you fall for the one person you can’t have?

Anna has always tried to do everything right, working hard through medical school, and now in her career as a doctor. She’s worked hard at her eight-year relationship with her fiancé Phil too, and can’t wait to get married and become part of Phil’s extended family. Then the unthinkable happens. Phil breaks up with her three months before their wedding. Luckily, Phil’s younger brother Seth works at the same hospital and is there to help her through the aftermath.
Seth’s always been the laid-back, jokey one in contrast to his more serious brother. He’s always secretly envied Phil’s relationship with Anna because she’s his epitome of the perfect girl. When he sees how devastated Anna is after his idiot brother dumps her, he does everything he can to get her smiling again.
But the more time they spend together, the more their connection grows.
Your brother’s ex-fiancée is off-limits. Everyone knows that.
The problem is when you accidentally cross that line, the repercussions can be immense.