Bedded Under The Christmastide Moon by Christina McKnight

THEIR MARRIAGE OF CONVENIENCE…
For years, Lady Melloria Whitmore has believed her childhood best friend and secret love Brigham Clarke agreed to marry her out of a sense of duty. Knowing how important Brigham’s work with Parliament is to him, she agrees to see him once a year, when he returns to his country estate for the holidays. This Christmas, Mellie vows to give Brigham the one thing he has always wanted: an heir. For one night, she’ll share his bed, and she’ll have that memory of passion to get her through the long winter nights without him.

IS ABOUT TO BECOME A MARRIAGE OF LOVE.
Except Brigham doesn’t want just one night—he wants forever. He’s loved Mellie all his life, and making her his Viscountess Whitmore was his dream. He just never thought Mellie returned his feelings. So when Mellie begins her seduction under the Christmastide moon, Brigham receives the best gift of all: his wife’s love.