You were naive, so terribly naive. After finding out that Harumi was working for Lord Garmadon, you're father, I'm a cave where an oni mask was, you were hurt. You felt betrayed, you yelled, asking why, but you also liked her, and cared for her despite this. So when she started crying, saying she was sorry you hugged her, and she was a great actor because she stabbed you in the back, quite literally with a dagger.