There already some complain about them having father-son relationship. Those guys didn't read the manhwa correctly.
From the start, Ryeong already stated their relationship as companionship when Paljae asked about them. That 'companionship' has no meaning in romantic ways, as at that time Ryeong thought that having a friend wouldn't be bad. Besides that, their past already tell that their first meeting is when Paljae in his adult body and Ryeong a teenager. Then fates separate them and only meet them at their now circumstances. So the dynamic of 'grooming' can't be justified.
Please don't make this story known to others