Love Reacquainted by Kate Rolin

She was a girl infatuated. He was a duke betrothed. Twelve years later, Olivia and Cyrus find themselves rather forcefully reintroduced thanks to Olivia’s match-making Aunt Elizabeth.
Tall, dark and handsome, Cyrus Dorn, the Duke of Alston, is exactly what most women would desire. However, bitter, resentful, and recluse are also accurate descriptors making him appear unattainable. Unable to cope after the loss of his first wife, Cyrus has sworn off any chance of loving—and losing—again.
Lady Olivia von Klor, now a widowed young mother to Josef, has made the decision to leave Austria and return to London to live with her aunt. Her priorities: secure a tutor for her son and eventually remarry—Josef needs a father. Ever dutiful, Olivia arrives ready to accomplish what she must, but all is thrown into confusion when she is greeted, not by Aunt Elizabeth, but Cyrus instead.
There is no denying the mutual attraction that grows as they become reacquainted, yet as Cyrus and Olivia come to terms with their feelings, obstacles threaten to end them—particularly their age difference and a handsome, yet secretive young tutor. Faced with love again, they must make a choice—is it worth the risk?