In for the Win by Melynda Price

To win his heart, she’ll have to give him the one thing that could drive him away—the truth…

Kyle Scott’s talent for fighting paved the way for a career he never wanted, but needed to survive. Five years later, he doesn’t recognize the man he’s become. All his focus and energy has been poured into raising his little sister, leaving no time or interest for anything beyond a casual hook-up—until he meets a woman who sends his life spiraling out of control.
Penelope Cantrel isn’t looking for love, but she’s always down for a good time. If she keeps everyone at a distance, they can’t discover how broken she is, or the secrets she’s running from. When she crosses paths with the sexy MMA fighter, Kyle’s reputation as a cage-banging manwhore doesn’t concern her. She isn’t interested in a commitment. But after their white-hot attraction leads to a night of mind-blowing sex, neither of them will ever be the same again.
When Pen starts receiving threatening messages, her deepest fears are realized as she becomes the obsession of a man who will kill to possess her. Concerned for her safety, Kyle offers to pose as her boyfriend to deter her unwanted admirer, but his heated touches and those not-so-innocent kisses don’t feel like he’s acting. Could the infamous playboy be falling for her?
As the threat against Pen escalates, her stalker is closer than they thought. Kyle is the only thing standing between her and a madman, but she fears trusting him with her secrets could be a fatal mistake.