Beautiful Bastard by Christina Lauren book in GUC.

An ambitious intern. A perfectionist executive. And a whole lot of name calling. Discover the story that garnered more than two million reads online. Whip-smart, hardworking, and on her way to an MBA, Chloe Mills has only one problem: her boss, Bennett Ryan. He’s exacting, blunt, inconsiderate—and completely irresistible. A Beautiful Bastard. Bennett has returned to Chicago from France to take a vital role in his family’s massive media business. He never expected that the assistant who’d been helping him from abroad was the gorgeous, innocently provocative—completely infuriating—creature he now has to see every day. Despite the rumors, he’s never been one for a workplace hookup. But Chloe’s so tempting he’s willing to bend the rules—or outright smash them—if it means he can have her. All over the office As their appetites for one another increase to a breaking point, Bennett and Chloe must decide exactly what they’re willing to lose in order to win each other. Originally only available online as The Office by tby789—and garnering over 2 million reads on fanfiction sites—Beautiful Bastard has been extensively updated for re-release.