His To Command - Self-Made Men, #1

From the moment John Fordyce saved Charlotte Clayworth from drowning at the age of five, the two of them have been inseparable. Trapped in a deserted farmhouse on a blizzardy Christmas Eve, John desperately struggles to control his desire for the woman he's grown up with. When a small act of discipline compromises Charlotte, honor requires John to make a marriage proposal different from the one he intended.
When Charlotte realizes she's in love with her best friend, she can't contemplate another man caressing her the way John does. But when he states they must marry to save her reputation and satisfy his honor, she refuses. The thought of their friendship dissolving into a marriage embittered by a single indiscretion horrifies her. Their friendship crumbles as they go their separate ways until a close-knit group of Self-Made Men decide to meddle in their mentor's love life and reunite the two lovers.
But will John and Charlotte realize they both have the same wish-that the best of friends make the best of lovers?