The long black hair one is the omega The short light color hair one is the alpha
The black long haired and golden eyes is the omega and the short small with the mustache is the alpha. This question was asked A LOT when the korean version came out. The insta accounts that does summaries and short translations were quite clear that the long haired gold haired one was the omega. Also it was confirmed on the authors tweet for the chapter and family picture. This was definitely heavily talked about when the korean chapter came out.
The small one with mustache is the alpha and the black hair one is the omega (≧∀≦)
Thank you all!!!
Which one of his parents is the alpha/omega?