Mistletoe Masquerade by Sahara Kelly

Butlers did not, in the general way of things, threaten titled guests. But then again, he wasn’t sure if butlers were inappropriately touched by titled guests that often. He sighed.
Being a butler was turning out to be quite a bit more complicated than he’d anticipated…
Paul DeVoreaux, the Inchworthy hunting box, near Pineneedle Drift, December 1814
They’re not butler or housekeeper; in fact, they’re not servants at all. Yet that is the pretense they must observe if their real identities and their whereabouts are to remain a secret.

For Paul DeVoreaux and Harriet Selkirk, fleeing London and the Ton is the best and safest idea at this particular time in their lives. A small hunting box in December is an even better one. Or so they think.
Thrust into the roles for which they are ill-prepared, Paul becomes a surprisingly effective butler, and Harriet assumes the role of housekeeper to the best of her ability. The arriving house party seems to find nothing amiss, and the seasonal revelries begin.
Unfortunately, the guests are nothing if not frisky, and Paul and Harriet find themselves forced into yet another masquerade. But this one isn’t quite as simple as donning a lace cap, or answering the front door…