On Her Majesty’s Secret Santa by Keira Candace Clementine

In a world where to lose means to die, MI6 agent Jack Sharpe only knows how to win. But has Sharpe finally met his match in his endlessly stressed handler, Jubilee Hall?
When a hard drive containing the identities of every British intelligence officer falls into the wrong hands, MI6 agent Jack Sharpe is sent to hide in the American town of Mistletoe. But he’s not going alone. Joining Sharpe is his handler, the perpetually frazzled Jubilee Hall.
Sharpe and Jubilee could not be more different. While Sharpe is charming, dashing, and coldly efficient, Jubilee is exasperated, tired, and a bit of a mess. While Sharpe moves like a shark, slinking through the world until he smells blood and attacks, Jubilee can’t get a paper cut without fainting. But when fellow MI6 agent Aleksei Trevelyan bets Sharpe he can’t win Jubilee’s heart, Sharpe starts to wonder whether he and Jubilee Hall are so different after all.