Maku ga Oritara Bokura wa Tsugai
Chap 3
Shinai Naru Omega e
Before Mio's heat, Keisei has already soften being with Mio as his assistant, he was just being tsundere, hard to himself. He's already like being together with him, but his hatefulness towards people can't disappear in short time. He's so stressed and got drunk himself when he saw his bro kinda close with Mio and depressed bcs he made Mio so tired as his assistant. So when Mio made him go crazy for his instinct as Alpha, he kinda disgusted himself and thinking Mio just being with him bcs of his nature as an omega. So, when he heard that Mio want Keisei for himself, he finally know for sure, he wants Mio too. As alpha and omega, claiming your mate and have such possessiveness is their nature. But didn't as human being sometimes we did it to our love one?
Ijiwaru na Tsukai no Netsu ni Oborete