He tried to control his emotions. Tried to keep his claws from digging into the door, which meant he had his hands balled into fists. He breathed heavy, but when he heard her call out to him, heard the worry in her voice. He exhaled and lowered his hands, slowly turning to look at his sister.
His fists balled up at his sides, as he kept his eyes closed and his mouth closed. When he saw his reflection that morning, he freaked out, punched the mirror. The last thing he wanted to do was freak out his sister.