Old flames and new fortunes : a novel / Sarah Hogle.

Enhanced descriptions from Syndetics:

A small, magical town tucked away in rural Ohio, Moonville is the perfect place for flora fortunist Romina Tempest to expand her shop, where she uses the language of flowers to help the hopeful manifest their love lives. After giving up on her own big romance eleven years ago, at least she can bask in the promise of others'. So, when the shop's potential financier shares news of his wedding, Romina jumps on the opportunity to discuss buying the business. What better place to negotiate a deal than at a wedding, even if she has to fake-date her chaotic colleague Trevor to get an invitation? But all hell breaks loose when she discovers Trevor's soon-to-be stepbrother is none other than Alex King: her high school sweetheart. Her greatest love. The boy who, eleven years ago, broke her heart, and who now thinks she and Trevor are dating. What starts as an innocent misunderstanding becomes a week-long fake dating scheme, as Romina resolves to make Alex pay for breaking her heart. The only issue? She can't deny their still-burning connection. Caught between proving to Alex what he lost, and coming clean and risking her business, Romina must decide whether giving Alex another chance means going back on herself, or finally releasing her hold on the past.