An intelligent story about culture shock and opposing values wrapped in the political intrigues of a historical fantasy. 
 If you've read the Memory of Scorpions series by Aleksandr Voinov, Sacrati has a similar vibe to it, in that you've got a warrior of an elite group embroiled in political intrigues that're rather against his nature; he'd rather be a fighter and follow orders than have to figure out what side is "right" or "wrong" and possibly take down a regime. (And try not to fall in love with an enemy in the meantime.) 
 The Torian Empire is made up of several valleys within a mountainous region. One of our heroes is from one of the westernmost valleys, Windthorn, which borders with the Elkati kingdom/region/valley. The men of the Torian empire all live outside the main city in barracks, and they specialize in fighting and nothing else. The women and children all live within the city walls, and they do all the other tasks: agriculture, crafts, smithing, healing, learning, etc. It's a system which works for them, though it is imperfect. Within the men is an elite group of fighters known as the Sacrati. They push themselves harder and band together more as brothers, though they do still fight alongside their non-Sacrati Torian warriors as well. 
 A band of Sacrati come across a band of Elkati who have traveled over their border. The Sacrati take them as prisoners and hike back to Windthorn. As leader of the Sacrati party, Theos is allowed to take one prisoner as his own personal property before the rest are tested to become warriors or are shipped back to the central valleys of the Torian Empire as tributes or menial labor. Due to an unusual set of circumstances, Theos takes Finnvid as his property instead of just requesting his value and selling him off to a trader. This upsets the local warlord (the leader of the Torian troops, though the Sacrati have their own captain who also reports to the warlord). Soon the weird circumstances begin to pile up, putting Theos in the middle of the warlord, the Sacrati, and the city (ruled by the women). 
 Eventually it comes out that Finnvid is of special interest to the warlord. He had been in communication with the warlord, and was attempting to put off the Torian invasion of the Elkati valley while gathering intel about the Torians. And what Finnvid discovers of the politics within the Windthorn valley could change the way the Elkati ally themselves. 
 But as with all good political intrigue stories, manipulation leads to misunderstanding, and mistakes are made which may prove to be too difficult to overcome, making a war inevitable. But first, the Torians have to figure out their own internal issues, and Finnvid and Theos have to decide where their loyalties lie, because now each as a better understanding of the people on the other side of the conflict. 
 Theos is loveable in his forthright honesty. He is without guile and wants to lead a simple life. Most of his issues with Finnvid come from his inability to understand the prudishness of the Elkati way of life, whereas Finnvid is unable to accept the sexual freedom, lack of commitment, and lack of freedom for men (to choose an occupation) in the Torian way of life. They do begin to find common ground slowly, but then secrets are revealed and transgressions occur which set them back before they can truly find each other. 
 Third person limited POV alternates between Theos and Finnvid. 
 If you're worried about cheating between the MCs, (view spoiler)[it doesn't happen (to our knowledge) after the MCs fall for each other. Theos lets a few guys suck him off on-page before he and Finnvid do anything together, and it is mentioned later on that Finnvid saw Theos do more in those initial weeks, but that's pretty much the sum total of detail. (They have to storywise for Finnvid to become interested in it himself since he was raised to believe men shouldn't lie with men.) But once they become enamored of each other, they don't do anything with anyone else. 
 There is mention of M/F relationships, and a M/M/F/F menage several years in the past, but these are only mentioned in passing. There are no M/F sexual situations on-screen. (hide spoiler)] 
 I would describe the end as HFN, and there are some open ends which could make for a possible sequel. I wouldn't be opposed to reading more of their story.