Love By Convenience by Deb Goodman

She agreed to marry him for the greater good.
How dare he fall in love with her?
Dashing and illustrious Mack Duncan is a shoo-in for mayor in the upcoming Silver Plum election. That is, until ghosts from his family’s past are dredged up, and he starts dropping like a rock in the polls. When his mom and her best friend tell him to ask the caring and beautiful school teacher, Cady Marshall, to join him in a marriage of convenience, he’s appalled.
Cady’s even more appalled at the crazy scheme. They can’t ask her to marry him just to help him win. But when she realizes that Mack becoming mayor is her hometown’s last hope of saving their water and her mother’s flowers, she agrees. Besides, this “wedding” will give her ailing mother the chance to see her child walk down the aisle.
As Cady and Mack are forced to spend nearly every moment together, their feelings begin to shift. But when the forces combined against Mack prove fatal to his election hopes, will Cady’s career dreams force them to say goodbye? Or can true love actually happen by convenience?