Well, he loved the seme when he was beta though.
If you read the novel you will find that he loved him since he was in university
I think the story progress of Yeonwoo is a late omega, so everyone assume that he is an Beta beacuse according to omegaverse of japan is that omega tgat are late are actively beta unless they find there ( what do you call that? A soul mate? I forgot) or someone has a powerful pheromones, you can see that in a omegaverse manga i think , i dunno but i know i read that , but Yeonwoo can still marry to emma you know...
better outcome than this bs
Yeonwoo was a beta before. He turns to omega because of Keith.
I can't help thinking if Yeonwoo stays as beta, he would be happily married with Emma who loves him and maybe have kids.