What was this military(?) romance book??

I need help to find this book I read online awhile ago! I dont remember the cover since it was online. The only detail I remember is it started with this guy doing interviews for someone to either join his team or be a bodyguard (but I think it's bodyguard), and the FMC makes a conscious choice to click her heels as she walks to his office, but doesnt allow them to click on the floor when she leaves and the MMC was so impressed.