Her Billionaire Bodyguard by Jo Grafford

After walking in her two sisters’ shadows most of her life, Bailey Maddox secures a promotion as Vice President of Marketing at DRAW Corporation. She is anxious to prove her worth to her hard-to-please family, but a series of threats propels her straight into the arms of a hunky bodyguard. Knowing her billionaire family will never welcome him into their inner circle due to his lack of wealth and social consequence, she resists the attraction that sparks between them.
Don Kappelman, ex Special Forces Weapons Sergeant, is in the business of serving and protecting. That includes looking after the stunning Bailey Maddox at a charity ball, even though he knows associating himself with a Maddox spells trouble. It also spells heartache when they share a kiss that she brushes off as simply part of his job.
Torn between old loyalties and new, past dangers and present ones, they play the game of hearts within the treacherous realms of the rich and famous.