Spoiler
It turns out that the father knew Seowon's condition since he was young, but chose to not tell him.
So when his father found out that he is pregnant. Of course, just like any father, he got angry. He is asking who the father is.
Then Seowon is not yet telling (they are still in the hospital) and he is scared to tell Aiden about his pregnancy and his condition because he is afraid that Aiden might not like him anymore because of him being a monster or something.
Not sure about the exact translation, but i think that's it?
Spoiler
So Aiden found out cause the dad told him and he flew back to Korea and he accepted. Then they were kissing on the hospital bed then Seowon's father saw them
Gosh I don't know how to feel about this anymoreeee.
Just a bit of spoiler. I am reading the raws and after Aiden left, they still communicated often. Then, Seowon started feeling sick, after a while.. specifically on Chapter 33, Seowon and his father decided to go to the doctor. Then the doctor said that, Seowon is pregant. Likeee?! Huh?! Hahahwha
Anyways the doctor said that there are some cases like that. And there's some kind of genetic mutation or something? And that is the reason why he is weak since he was a kid as per the doctor.
Also, the doctor only talked to Seowon privately. I haven't finished the chapter so I don't know the father's reaction yet.