Risky Chance by Tabitha Marks

Being the single father of a preemie at twenty-five was not what Keith Lane envisioned for his future, but after a one night stand, that’s exactly where he ends up – juggling work and caring for his son, and struggling to keep it all together.
Sara Saunders has a heart of gold and a sweet disposition, and wants nothing more than to have a relationship with her nephew. When she finds out Keith needs a nanny it seems like the perfect solution ¬– Keith needs help, and she’s the most qualified candidate he could ever hope to find!
Despite his initial reservations and instant attraction to her, Keith takes a risk and hires Sara. Sparks fly and he soon realizes that he wants her as more than just a nanny, but Sara’s habit of acting without thinking lands her over Keith’s knee before they even have a first date.
Luckily, Sara craves the discipline and structure that Keith can provide, and their relationship thrives. But when the past shows up on his doorstep Keith questions everything he thought he knew about Sara, and wonders if taking a chance on her would turn into the worst mistake of his life.