Responses
i think they are not blood related siblings cause you can see on the previous chapter where seo in's family were together again because of his brother's death anniversary, they were talking about like, him taking back his position something like that in their family
So lookin back on this...didnt seoin kiss his twin brother in ch 2 like look at their birthmarks… (or maybe the twin kissed seoin/black hair mid fight without consenting to it…BUT THEN WHY DID black hair CLOSE HIS EYES while KISSIN). Bye this is weird..foreseeing this takin in some incest to the drama