Falling in Love by A Mistaken Vow

Luca is allergic to women—until a drunken night ties him to Isla in a marriage neither remembers. He flees abroad, she struggles for her mother's medical bills. A year later, he finds Isla is the only woman he's not allergic to—and makes her his contract girlfriend. Sparks fly… until the twist: the "spouse" they tried to escape is each other!