The Cordial Bride by Samantha Cayto

Being a bride is a state of mind, not of body.

Ian, Count of Charteris, is happiest when he is working his land with his tenants. Court life and travel hold no appeal for him. Nevertheless, he escorts his widowed sister on a diplomatic mission to the isolated Shadow Valley. Rumor has it that those people have discovered a miraculous medicine that Moorcondia is anxious to trade for. Boredom transforms into fascination at the sight of a beautiful creature who welcomes him to the Valley.
Calan is an orphan raised by his powerful aunt. He has learned the craft of healing but cares little for politics, preferring a life outdoors. As the first of his people to see the Moorcondians, he is surprised by how virile Ian is. Here is someone who can introduce him to the pleasure to be had between two men.

The personal becomes the political as undercurrents of distrust and intrigue impede the possibility of a treaty. It is up to Ian and Calan to forge the path forward before their fairytale turns into a nightmare.