The signs were always there but y'all just didn't want to see it. The way Taegu have always acted whenever seo-in was in the room, his body language with yeongwoon whenever seo-in is mentioned has always proved that he saw seo-in as a love rival.
God forbid I didn't want his father figure to actually wanna fuck him (I def saw the signs too and I honestly love the way ts is written bc you never see that from the way yeongwoon acts around him. adds more layers to their interactions until now)
The signs were always there but y'all just didn't want to see it. The way Taegu have always acted whenever seo-in was in the room, his body language with yeongwoon whenever seo-in is mentioned has always proved that he saw seo-in as a love rival.