Specific Recommendations Wanted in the Vein of Tom Lake by Ann Patchett

I just finished listening to the audiobook of Tom Lake by Ann Patchett and loved it so much. I want to read more books like it, but first I really became interested in reading a book that is similar to Tom Lake in one specific way.

I would like to read a book that is more romance than Tom Lake was, but deals with someone starting a relationship with one person and then, through the course of the story, finds love with someone else entirely, someone unexpected. I’ve only read one book like that from what I can remember and I didn’t really like it. But if anyone has recommendations for a book like that please let me know!