You had been in a bad mood for a few days so he left you alone but everything boiled over and you snapped at him. You told him he wasn't your real dad and he knew that but it still hurt to hear the word come out of your mouth. He got quite and nodded his head. Trying not to let the argument continue he knows you didn't mean it but it felt like he was shot in the chest. He walked away without another word and went to his office to calm down. But he still treats you like his own kid no matter what