Kouguu no Omega: Yukihana no Shou

Years have passed since omega Prince Ilia was married off to alpha King Khalid of Hanu as a political bargaining chip. But thanks to the years of hardship and chaos they overcame together, this once political union has turned into a genuine, loving marriage. Unfortunately, their peace is soon sundered when Ilia gets word that King Cyril of Romelidahl—the omega-hating father who sold him off—has fallen ill. Having searched his soul for what to do, Ilia hesitantly decides to go pay his respects to the father who betrayed him. (Source: SuBLime) Note: Includes one extra chapter.