Fates and Furies by Lauren Groff

This novel is about a relationship over time, which is one of my favorite fictional subjects.  The couple meet in college and marry quite quickly.  At first glance it seems to be entirely of Lotto's doing, but as the book unfolds we find that Mathilde is not who she appeared to be at first, and that she may have had more than a little influence on the elopement than it first appeared.  She appealed to Lotto because of her innocence, but in reality she was living with a much older man as a sort of concubine, which he finds out much later.
They start out as young and in love, but also broke and cut off from Lotto's family and their money.  He is a struggling actor until Mathilde encourages him to write plays, and she is the one who gets the first one produced, and then he is off to success.  The rest of the book is the juxtaposition of Lotto's view of the relationship with Mathilde's, and the inevitable differences therein.  It is an interesting read, one that makes one reflect on one's own love life.