Her Bodyguard - Ann Tosti

Lennox Lawson is the young, billionaire CEO of her family's company. It's a lot of responsibility on the young woman's shoulders, but one she's been preparing for her whole life, even if they hadn't expected her to take over so soon. Her younger brother owns it with her as the CFO, but she still feels like she has to show how strong and capable she is. Which means she can't let on that anything is wrong.

But her brother sees anyway and calls his best friend to find out for him.

Max Knight is newly a civilian again after finishing his service in the Marines and looking for his new career. When his best friend calls him to ask a favor, he doesn't hesitate to step in. Especially when that favor is to find out what his best friend's sister- his first crush- is hiding. And when that turns out to be a stalker, he's not going to let the love of his life out of his sight.