Romance novels about MARRIED people.

I'm still chasing the high from Outlander. I'm looking for a sweeping romance novel where the main couple is married for at least half of the book. I want to see the established love and trust as they face the adversity of the world. I've also really enjoyed The Time Traveler's Wife. Please no cheating and I don't want saving a crumbling marriage to be the central theme of the book.

Edit.
Peaches and Honey by R.Raeta is another favourite duelology about a married couple.