My guess is that before he was lost, Chan when into heat so severe that he forgot he had sexual contact with Taesan. It's the only thing I can think of, because clearly Siwoo is Chan's baby. I'm also pretty surprised no one pointed Siwoo's eyes until the nanny did it. Maybe the eye color is pretty common in this world? And Chan is really clueless about what happened to Taesan. I think Taesan ran away because he knew he was pregnant with Chan, think he will ruin Chan's life or what ever and didn't think he was gonna be attacked by the coach
My guess is that before he was lost, Chan when into heat so severe that he forgot he had sexual contact with Taesan. It's the only thing I can think of, because clearly Siwoo is Chan's baby. I'm also pretty surprised no one pointed Siwoo's eyes until the nanny did it. Maybe the eye color is pretty common in this world? And Chan is really clueless about what happened to Taesan. I think Taesan ran away because he knew he was pregnant with Chan, think he will ruin Chan's life or what ever and didn't think he was gonna be attacked by the coach