Mister Wrong by Nicole Williams

Cora Matthews grew up with the Adams’ boys, twin brothers and best friends who wouldn’t let anything come between them—except for her. One of them became her best friend; the other, her fiancé.

She always knew she’d wind up marrying one of them, and Jacob Adams is the epitome of Mister Right. At least until he fails to show up for their wedding.

As Jacob’s best man, and identical twin, Matt makes a split-second decision that will affect the three of their lives forever—he steps in to take his brother’s place. In front of the altar, exchanging vows with the woman he’s secretly been in love with for years.

But Cora finds out about the groom swap. The morning after the wedding. As if realizing she just slept with her fiancé’s brother isn’t disturbing enough, she’s forced to confront the feelings for Matt Adams she thought she’d buried years ago.

Through the course of her real honeymoon with her fake husband, she uncovers truths both Adams brothers were hoping to keep hidden, for opposite reasons. One to protect himself, the other to protect her.

She married the wrong brother, but what if he’s been the right one all along?