
Originally Posted by
Adam_Prince of Eternia
Duncan elaborates on this in episode three. Teela questions his willingness to abandon his responsibilities to the crown, and he replies, "No, my responsibility was to protect Adam." That was his entire job: to mentor and protect Adam. (Especially, if Adam is the only remaining child of Randor, because Skeletor helped kidnap his daughter.) To find out that not only did Duncan fail to protect his son, but that he actively put him in harm's way, would be infuriating. It did not have to be. Not only did he lie to his king, but to his friend, who trusted him with the most precious thing to him in the entire world. He trusted Duncan with the life of his son, and Duncan could not trust him with Adam's secret. Then to realize that everyone in that room knew except you, and you look foolish in front of everyone. Then you feel guilty, remembering all the times you criticized him without knowing he was Eternia's greatest champion, before realizing that the last thing you said to him was not, "I love you," but "I am not proud of you." His reaction was entirely understandable.
As was Teela's. She is an orphan. She does not know her birth parents. She feels abandoned. The people in that room are the closest thing to family for her, and every single one of them knew Adam was He-Man, and did not tell her. She was good enough to be their Captain of the Royal Guard, to be their Woman-At-Arms, but not to be included in their conspiracy. That tells her that even here, she is an outsider. That she does not belong here or anywhere. Her birth parents did not want her, and her adopted father did not trust her enough to tell her the truth. Let alone her best friend, the man she is secretly in love with. It makes her question everything: "What other things are the Royal Family keeping from me? Can I even trust them enough to serve them with my life now? Does my father really love me? Would he have told me the truth if I was his real daughter? Did I really know Adam? Did he not trust me? How can I trust my feelings for him now that I do not know where we really stood?" Then Randor threatens the life of her father, and commands her to exile him. I would say that warrants a pretty strong reaction.