Preach
He was not only following orders. He said it was out of duty (and paying back his debt), but more importantly it was also self interest. He wanted to become the sort of person whom no one could look down upon. He's not just being shallow and evil thought, there's other complicating factors. He was trying to focus on the bigger picture and believed that not letting outlanders invade was the highest priority. And if to achieve that he had to commit morally reprehensible acts, he would make that sacrifice. Because as he said, it was lesser of the two evils. There are other factors also complicating the situation more so it's not as black & white as it seems. It seldom is. But this is the gist of it.
He actually saw his dad getting killed by him! Lost his only brother as a direct result of this dude's actions, sold as slave, got buggered and turned into male prostitute. He better be playing a long con and exact the coldest mf revenge!
Can't believe the justification that he was only obeying orders therefore it's ok for mc to fall in love! How the heck is that realistic? The pretty art and buff top have lulled us all.