Colonel Daddy by Carolyn Faulkner

Military Daddies - Book 4

After jettisoning her serial cheater husband, Carrie Leighton retains custody of his best friend, for whom she has lusted for quite some time. Newly minted Lt. Colonel Heath Forrester has always preferred his best friend's wife to his waste of humanity best friend. And he might actually have a chance with her - as long as she never finds out that he knew - all along - that her husband had been sleeping with multiple other women.